Moneyball: Recreating Willi Castro in the Aggregate

Willi Castro has arguably been the Twins' most valuable player for two years running. He’s played passable defense (or better) at six of the eight defensive positions; that led to him getting votes for a Gold Glove Award in 2024. The crafty righthander has even given the team 3 ⅔ shutout innings on the mound. Over the last two seasons, he has 916 at-bats, boasting a .251/.334/.395 slash line with 80 extra-base hits, 94 RBIs, and 47 stolen bases, all while carrying a 23.9% K rate and 8.1% BB rate.

Castro’s journey to the Minnesota Twins has been well-documented: After four-ish below-average seasonswith the Tigers, he was non-tendered in November 2022, and a month later, the Twins signed him to a minor-league deal. He’s the ultimate underdog story and, boy, do people love rooting for an underdog. But sometimes that story can blind us from reality, as was the case with Randy Dobnak and Willians Astudillo. Those two guys were easy to root for and fun to watch, but even when the production waned, we heard plenty of fans clamoring for bigger roles because of their backstories. Could the same thing be happening with Castro? Could the Twins be better served to non-tender Castro and replace his production through multiple avenues?

Admittedly, prior to reading Nick Nelson’s tweet, I thought it was a no-brainer that Minnesota would bring Castro back. After all, FanGraphs values his production at $43.6 million over the last two seasons, so how could you say no to a salary that is projected to be roughly a quarter of his annual worth?

But Nick forced me to take off my underdog-colored glasses and really think about the value Castro provides, in the added context of the Twins' self-imposed salary cap. Why spend that much on a utility man with a 108 wRC+, when you could spend a fraction of that on a prospect to leave some room for reinforcements elsewhere? Or as Brad Pitt told us in Moneyball, the Twins may be better off trying to recreate him in the aggregate.

Enter Yunior Severino.

The 25-year-old Severino signed with the Twins back when he was a teenager, after the Braves were sanctioned for violations of IFA signing rules and he was declared a free agent for a second time. Despite posting above-average numbers from 2019-23 from Low A through Double A, the switch-hitter never really found himself gaining the prospect pedigree that you might expect of someone who keeps performing well at multiple levels. Regardless of what outsiders thought, the Twins viewed him as a valuable asset to the organization and (somewhat surprisingly) added him to the 40-man roster last November–protecting him from the Rule 5 draft. What did the Twins see that others didn’t?

Well, we know that the Twins really, really value versatility. Throughout his minor-league career, Severino has bounced around the diamond, seeing time at every position aside from pitcher and catcher. More recently, looking at the 2024 season, the utility man saw time at first base, third base, and right field. Various scouting reports indicate that his defense is not a strength, evidenced by his positional versatility shrinking with each season. That said, he can play mostly anywhere if it’s needed, and when you have a bat like his, there is value in that.

With the St. Paul Saints, Severino had a .254/.342/.434 slash line, with 21 homers and a solid 12% walk rate. His plate discipline and swing decisions are very solid and, while strikeouts have been a concern over his career, a 27.3% K rate in 2024 is an improvement compared to his stint at the same level in 2023. The elevated strikeout rate can be partially attributed to his all-or-nothing approach at the plate, as he has a below-average contact rate of 66.7%. But, once again, that number is an improvement over what we saw in 2023, which is encouraging to see from a prospect. So, can Severino really be considered a Willi Castro replacement?

Short answer: no. But there’s more nuance than that – it’s not black and white.

Again, this comes back to money. While Severino is a clear downgrade from Castro, if the Twins elect to “save” money here allowing them to spend elsewhere, then we could be looking at a situation where they’re getting more bang for their buck. Instead of paying "just" Castro, what if the Twins can pay Severino, plus one or two relief arms that help bridge the gap between the starters and the back end of the bullpen? What if, given the versatility of Austin Martin, Brooks Lee, Royce Lewis, and José Miranda (in addition to Severino), there is less of a need for super utility than there was the last two seasons?

Going back to Moneyball, the Twins shouldn’t be focusing on how they can replace Castro, but how they can recreate him in the aggregate. With that in mind, I no longer think that Castro is a lock to be on the Twins' 2025 roster. In fact, I may have been swayed to the other side of the argument. While his contributions have been more than expected and greatly appreciated, maybe it makes the most sense to non-tender him in a month and find value elsewhere.

What would you do in this situation? Join the conversation in the comments!