Willi Castro is Worth More than WAR Can Say

[Greggory Masterson]

Put away your abaci, nerds. Willi Castro changes the definition of a replacement player.

Image courtesy of © Matt Blewett-Imagn Images

Okay, maybe “changes the definition” is a bit extreme, but stick with me here. A Willi Castro-type player alters team construction and decision-making in a way that’s unique to a small subset of players, even if he’s not an elite player in and of himself.

The Twins have a decision ahead of them. It’s a decision that probably isn’t so tricky but for the apparent need to keep payroll tight ahead of 2025, but here we are. Willi Castro, their do-everything man, is due for about $6.2 million in arbitration, according to MLB Trade Rumors’ projections.

Castro earned himself some recognition this season, being named an All-Star and a "finalist" for the Gold Glove at the utility position (whatever that means). He was about 5 percent better than the average hitter, starting more than 25 games at five different positions (including shortstop and center field). He led the team in both games played (158) and plate appearances (635). For the analytics wonks out there, FanGraphs had him at 3.1 WAR, and Baseball Reference had him at 1.6.

He produced like a solid starter. The All-Star nod was based on his electric first half, and he saw a significant drop-off in the final three months of the year, but production is production. He’s not a great defender at shortstop or in center field, but he can play there well enough to get you by. He’s the quintessential 10th man, and there are few like him.

Sure, there are players who can play multiple positions on every bench, but it’s rare to find one who can both hold his own at the plate and cover the more challenging positions. And that has ripple effects.

First, he’s a starting-caliber player who can replace anyone. Should injuries (or ineffectiveness) happen at any position, Castro can cover that spot for weeks at a time, as he did in 2024 at second and third base, shortstop, and center field. There’s value in that, by itself. If a team’s best bench option is a utility infielder, that guy can’t cover center field. If the team has a solid corner outfielder on the bench, good luck teaching him third base.

In such cases, teams have to skip over their top players for their second or third options. That’s not so with Castro. Even though Castro doesn’t play right field often or first base at all, all those positions require is a slide across the field from one of the team’s other starters. He can handle it everywhere else. You don’t have to skip over Castro to get to someone else.

Second, Castro’s flexibility allows more creativity in bench construction. The modern four-man bench in MLB looks something like this: backup catcher, backup infielder, backup outfielder, free space. It's pretty straightforward with the backup outfielder and infielder—if the team loses a player in the infield, the bench guy comes in to take his spot or some sort of realignment, and it’s the same for the outfielder. In this setup, a massive part of who ends up on the bench for the team is coverage. There’s no hole one of those first three guys can’t fill.

But what if one guy can cover both?

That’s Castro (and a select group of other players in the majors, like Houston’s Mauricio Dubón). Because Castro can hit and play six and a half positions (like, I guess he’d play right field in an outfield alongside Austin Martin and Byron Buxton), a team now has two free spaces. If you want a big bench bat, go for it! A mostly platoon hitter? Why not! Carry both! You can justify a roster setup that you wouldn’t be able to without Castro being both your utility infielder and outfielder. The situational and functional effectiveness of the bench just went up.

Note: Of course, this only works if the other role players on the bench also fulfill their bit roles and aren’t stretched past their capabilities (see M. Margot, Minnesota Twins, 2024). However, that’s true of all benches and roles. Form follows function and all that.

In these cases, though, the positional component is reduced. The team has coverage. You don’t need to place as much emphasis on having a glove-first infielder as you would have otherwise. It would be nice to have a better option defensively up the middle, but Castro reduces that need and allows more roster construction flexibility.

Third, and here we’re getting to the replacement player part (I know Chekhov’s Gun; I don’t leave those loose ends), Castro affects who the team’s replacements are. You know, those hypothetical replacement players freely available at Triple-A, or on waivers, or free agents, or whatever. With Castro, you get the pick of the litter.

Let’s consider a 2025 hypothetical scenario. Royce Lewis, everyday second baseman, gets hurt. He needs to go on the IL. The top infield option for a call-up is Michael Helman. The top outfield option for a call-up is Emmanuel Rodriguez. Sight unseen, who would you prefer to get the call?

Well, if your Kyle Farmer-type is moving into an everyday role, you probably want the infielder. Suppose your Willi Castro is moving to an everyday role. In that case, you might have some room for your top prospect to get some time in the outfield, taking Castro’s time out there now that that’s free, given that the initial plans would include him playing a little on the dirt, a little in the outfield, pinch running, platooning. After he’s tied down, there’s playing time everywhere else to be had.

In truth, we never really saw how Castro’s versatility would have played out as a primary bench player, in which he would have time spread out around the diamond and been used situationally as he was in 2023 (see this Ben Clemens article on depth charts, if this stuff interests you). Instead, he was thrust into the starting lineup in the second game of the season after an injury to Lewis.

And that’s the fourth effect. A Twins team that is as injury-prone as this one needs a Castro. Not every team relies on so much production from players who are injured so often, and to an extent, having a solid 10th man allows some risk-taking. That doesn’t show up in his statistics, but it’s another effect. A team with a strong bench or competent high-minors bats is tooled to withstand the injury bug better than the average team, and for the Twins, that’s not something that they can afford to forego. A team can only feasibly carry ten everyday players, but not every team can get to that number. A Castro-type makes that possible.

Castro’s effects aren’t neatly summed up in a WAR number or stat line. Those still look nice, but some value is in the value that a player creates in the spots on the roster that they don’t occupy. It’s one of the reasons that Shohei Ohtani’s two-way abilities are so valuable, beyond his quantifiable production. His team has the freedom to do a little more with the spots around him.

Note 2: If you read those last two sentences and think that it says “Willi Castro and Shohei Ohtani are equally valuable,” so help me.

Naturally, none of this holds up if Castro is closer to the player that he was in the second half of 2024. Hopefully, any Castro decisions this offseason will be made based on how skilled the team believes he is, rather than the moderate sum he'll be owed. If there's a tiebreaker to be found, though, let it be the unmeasured value of the flexibility boost he provides.

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[Jocko87]

I would argue that if there is a payroll issue, this player type is more valuable than ever.

It's the same argument I made with Farmer last year.  It's 2m for the player and 4m for the insurance policy.  Much better coverage than Farmer too.

[Doctor Gast]

I'm with you Greggory, WAR doesn't tell the whole story. If you hit a bunch of HRs, you'll have high WAR (no defense or hitting are necessary) otherwise you have to be exceptional in defense (especially in a prime position) or hitting to amount to anything. Let alone the very important intangibles that are not included. Castro's intangible flexibility in playing multiple positions well & switch-hitting is huge in filling in where he's needed when someone is injured, that's why he's the Twins MVP. Valuable players are someone you hang onto, not trade away to cut salary. You find other ways to do it, like not spending on frivolous salaries & making sensible & necessary trades instead of going to FA. 

Cutting salary wasn't to blame for our bad season because trades could easily be had to fill our holes. But the decisions that were made to do it, were critical in the chemistry & gaps in positions. But where cut in salary hurt, was not extending players like Castro last offseason where it'll cost us more in the long run to extend them or even losing them (which will continue to contribute to the team's decent).

[thelanges5]

Sign him now to a 3 yr deal. 
year one 4 mil

year two 6 mil

year three 8 mil

Agree with the ToffDaily podcast in that he is not the primary CF backup. They need someone else for that  

 

[Vanimal46]

26 minutes ago, thelanges5 said:

Sign him now to a 3 yr deal. 
year one 4 mil

year two 6 mil

year three 8 mil

Agree with the ToffDaily podcast in that he is not the primary CF backup. They need someone else for that  

 

Add about 2 million to each of those years and maybe he considers it. Why would he take $2 million less than what he’s projected to get in arbitration?

[DJL44]

There is a difference between "offseason" replacement value where there are tons of freely available players ready to fill in the margins of your roster and "in-season" replacement value where you are limited to your own organization or whoever gets dumped on the waiver wire. You are right that having someone like Castro allows for more in-season flexibility when determining who gets called up in the Twins organization. That has value that is not captured in WAR.

[LambchoP]

I like Castro and hope we keep him. He might not be the best option as the primary backup SS or CF, but he's solid at every other position he plays. As we all know, injury insurance is always going to be needed on this weak and brittle team of ours. That said, Twins are broke and need salary relief so I wouldn't be surprised if he's traded. Unless he's moved along with someone else though, would 6 million really be enough to upgrade the team in any meaningful way? Who would replace Castro's innings then? Martin? Keaschal, Eeles? If one of these guys could step up and be a quality utility guy I could stomach trading Castro, but until they actually do, I don't think getting rid of our teams mvp will help our offense or defense. Unless by adding in Castro, a team will take Vasquez' salary. 16 million would give us some options. Then again though, we'd need to sign d backup catcher and utility guy.....will be interesting to see how Falvey works this off-season. Knowing him and the state of the team, I'm not expecting much. Maybe one trade and a couple bargain bin relief pitchers coming off of injury.

 

[thelanges5]

2 hours ago, Vanimal46 said:

Add about 2 million to each of those years and maybe he considers it. Why would he take $2 million less than what he’s projected to get in arbitration?

Okay add another mil to year two and year three. I guess my thought was give him a longer-term guaranteed deal and back weight it to give us financial flexibility for 2025.

[Jeff K]

I am a big fan of Castro.  That said, I'm going to go another way.  I think the Twins place too much value on position flexibility and not enough on position excellence.  This is not the fault of Castro, however, he should play less positions and play them better; which I feel almost certain would be the case if he were allowed to focus.  He may well be our 2nd baseman next year and if that happens, I believe he will flourish.

[Aerodeliria]

Sounds like a similar conversation we had about Nick Gordon......

[stringer bell]

52 minutes ago, Aerodeliria said:

Sounds like a similar conversation we had about Nick Gordon......

Disagree. Gordon is not and was not as versatile as Castro. Nick was never more than an emergency replacement at third or shortstop and was protected from left handed pitching. Gordon also isn’t and wasn’t the type of threat on the bases that Castro has been for the Twins, particularly in 2023. 

[bean5302]

Willi Castro can only play 1 position at a time, and he's playing every day so no matter where you move him to, you're automatically subtracting Castro from starting in the preferred location.

The only way Castro adds significant value with flexibility is if the Twins have adequate depth at the position Castro is vacating.
This type of scenario is the only way in which Castro's utility actually adds value.
Castro is the 3B and he's worth 3 WAR there and he's worth 3 WAR in LF.
The 3 WAR starting LF gets hurt. The Twins' hypothetical 4th outfielder is only worth 1 WAR
The Twins' hypothetical utility bench guy is worth 2 WAR at 3B.
Result = Left field is neutral instead of losing 2 WAR by putting the 4th outfielder there, 3B loses 1 WAR with the utility guy covering Castro's primary position, Twins are up a net 1 WAR.

In the scenario above, if the bench guy is worth 1 WAR, the Twins gain nothing. They're just reorganizing the deck chairs on the Titanic as it sinks. Basically, positional flexibility from an every day player is worthless if you don't have depth behind the flexible player: you're just robbing Peter to pay Paul as they say.

[sun]

IMO the Twins will pay Willie's arbitration salary next year & keep him. But beyond that he needs to prove that the bottom won't drop out again. Players of his caliber seem to perform better when they're on short term prove it deals. I doubt that the Twins will have room for him in 2 years if they want to take full advantage of their farm system by bringing up the best prospects. The chronically injured players need to prove that they can be more durable too so the FO will wait before extending Willie to see how it all pans out. 

[Aerodeliria]

4 hours ago, stringer bell said:

Disagree. Gordon is not and was not as versatile as Castro. Nick was never more than an emergency replacement at third or shortstop and was protected from left handed pitching. Gordon also isn’t and wasn’t the type of threat on the bases that Castro has been for the Twins, particularly in 2023. 

Of course, I think Castro is a superior athlete and player to Gordon; however, there was a lot of chatter about keeping Gordon around because of his versatility and potential--not from me--but you must admit that these things were talked about right here on TD.

The question is what is Castro really worth? More than Gordon to be sure but how much more? As a utility player, IMHO, he's worth the price of a good utility player with speed. If the actual goal is to play him at a particular position for the year, then one should compare him to others playing that position....

PS-Someone just said this very thing about Gordon in: "One Key Offseason Question the Minnesota Twins Face at Each Position"

[Mike Sixel]

For a budget constrained team, he's worth a lot, imo. I just dont know what they plan..

 

[stringer bell]

7 hours ago, Aerodeliria said:

Of course, I think Castro is a superior athlete and player to Gordon; however, there was a lot of chatter about keeping Gordon around because of his versatility and potential--not from me--but you must admit that these things were talked about right here on TD.

The question is what is Castro really worth? More than Gordon to be sure but how much more? As a utility player, IMHO, he's worth the price of a good utility player with speed. If the actual goal is to play him at a particular position for the year, then one should compare him to others playing that position....

PS-Someone just said this very thing about Gordon in: "One Key Offseason Question the Minnesota Twins Face at Each Position"

I, for one, have never viewed Nick Gordon as more than a stopgap, thus not comparable to Castro. 

[bean5302]

12 hours ago, Aerodeliria said:

Of course, I think Castro is a superior athlete and player to Gordon; however, there was a lot of chatter about keeping Gordon around because of his versatility and potential--not from me--but you must admit that these things were talked about right here on TD.

The question is what is Castro really worth? More than Gordon to be sure but how much more? As a utility player, IMHO, he's worth the price of a good utility player with speed. If the actual goal is to play him at a particular position for the year, then one should compare him to others playing that position....

PS-Someone just said this very thing about Gordon in: "One Key Offseason Question the Minnesota Twins Face at Each Position"

Was Gordon (who was very bad) really that much worse than Margot at $4MM or Farmer at $6MM? I advocated keeping Gordon because he was league minimum, had versatility, and his bat was good in 2022. There wasn't much to lose, and there were better places to spend money.

[DJL44]

15 hours ago, sun said:

IMO the Twins will pay Willie's arbitration salary next year & keep him. But beyond that he needs to prove that the bottom won't drop out again. Players of his caliber seem to perform better when they're on short term prove it deals. I doubt that the Twins will have room for him in 2 years if they want to take full advantage of their farm system by bringing up the best prospects. The chronically injured players need to prove that they can be more durable too so the FO will wait before extending Willie to see how it all pans out. 

Castro is a free agent after 2025. Unless the Twins give him a contract extension this offseason there is no "beyond that" to worry about.

[DJL44]

16 hours ago, bean5302 said:

In the scenario above, if the bench guy is worth 1 WAR, the Twins gain nothing. They're just reorganizing the deck chairs on the Titanic as it sinks. Basically, positional flexibility from an every day player is worthless if you don't have depth behind the flexible player: you're just robbing Peter to pay Paul as they say.

Positional flexibility gives them more depth to pick from. If someone gets injured they can pick from 6 different position players in the minor leagues to replace that player on the bench with Castro moving to the injured player's position. I believe there was part of last season where Buxton, Keirsey and Rodriguez were all injured at the same time but the Twins didn't have to reach down to AA to call up a centerfielder because Castro is on the roster. I think it happened again later in the season when Correa and Lee were both hurt at the same time and they used Castro at SS.

I will agree that Castro has the most value when he's the 10th player on your roster and is only playing every day because he is filling in for an injured/resting starter.

[bean5302]

6 minutes ago, DJL44 said:

Positional flexibility gives them more depth to pick from. If someone gets injured they can pick from 6 different position players in the minor leagues to replace that player on the bench with Castro moving to the injured player's position. I believe there was part of last season where Buxton, Keirsey and Rodriguez were all injured at the same time but the Twins didn't have to reach down to AA to call up a centerfielder because Castro is on the roster. I think it happened again later in the season when Correa and Lee were both hurt at the same time and they used Castro at SS.

I will agree that Castro has the most value when he's the 10th player on your roster and is only playing every day because he is filling in for an injured/resting starter.

Right. If there is depth on the roster, Willi Castro's flexibility potentially adds value. AAA replacement players are not legitimate "depth." A full example.

Willi Castro is playing RF (3.0 WAR) because Matt Wallner (4.0 WAR) is hurt. Royce Lewis at 3B (3.0 WAR) gets hurt so the Twins move Castro to 3B (3.0 WAR) instead of playing Lee there (0.0 WAR). Austin Martin moves to RF (0.0 WAR) to cover the position.
The Twins lose 3 WAR to have Martin replace Castro in RF.
The Twins gain 3 WAR to have Castro cover 3B to prevent Brooks Lee from playing there.
The Twins call up Deshawn Keirsey from AAA to keep the bench warm and get coffee from the locker room. (0.0 WAR)

Castro gives a net +0 WAR for flexibility.

[DJL44]

6 minutes ago, bean5302 said:

Right. If there is depth on the roster, Willi Castro's flexibility potentially adds value. AAA replacement players are not legitimate "depth." A full example.

Willi Castro is playing RF (3.0 WAR) because Matt Wallner (4.0 WAR) is hurt. Royce Lewis at 3B (3.0 WAR) gets hurt so the Twins move Castro to 3B (3.0 WAR) instead of playing Lee there (0.0 WAR). Austin Martin moves to RF (0.0 WAR) to cover the position.
The Twins lose 3 WAR to have Martin replace Castro in RF.
The Twins gain 3 WAR to have Castro cover 3B to prevent Brooks Lee from playing there.
The Twins call up Deshawn Keirsey from AAA to keep the bench warm and get coffee from the locker room. (0.0 WAR)

Castro gives a net +0 WAR for flexibility.

Willi Castro is not in the lineup until one player gets hurt.

Instead of Wallner + Lewis (7 WAR) you have Castro + Martin (3 WAR) instead of Lee and Martin (0 WAR). Castro gives a net +3 WAR because someone is ALWAYS hurt on an MLB roster. Plus, if one of your AAA subs is actually decent but blocked you can pull them up and move Castro to a different position. That sub would tally the 1 WAR but Castro is the player who enabled that move instead of grabbing the -1 WAR player from Double-A.

[sun]

1 hour ago, DJL44 said:

Castro is a free agent after 2025. Unless the Twins give him a contract extension this offseason there is no "beyond that" to worry about.

The Twins certainly can sign him in 2026 as a free agent which is how they signed Correa. As far as comparing WAR of players competing for playing time, those stats are all in the past tense & don't account for any future progress. Who would have thought that Arraez would have become a batting champion? Every MLB team treats players like they're expendable because they are. It's a meat market & I'm not sure that the Twins are convinced that they need to sign Wilie to a 3 year extension. Right now he has another year to prove himself because he's not going to take any pay cuts & there are other players that they need to make decisions about, both vets & prospects. I'm hopeful that they'll keep Willie for 2025 but beyond that I expect some new blood will be joining the team. Just wait & see if the team is sold & if Willie can improve his worth next year or not. IMO there;s no outstanding reason to rush an extension but there are reasons for the process to go slowly.

[Fatbat]

Pay the farmer buyout, pay castro and a rookie contract and you are money and production ahead in ‘25 compared to ‘24. Easy math.