It is beyond obvious that Jorge Polanco is essential to this Minnesota Twins team. Polanco's offense at the top of the lineup provides all-star level production, despite being on the most questionable defensive shortshops in the league. You could make a convincing case that he was the MVP of the team in 2019. With that out of the way, let's play a twisted game of "What If?".
What if Polanco goes down with an injury in 2020? It's not inconceivable, as he had offseason surgery for an ankle impingement, but the Twins anticipate him being ready for Spring Training. Even with that reassurance from the team, you'd rather have the starting shortstop come into Spring Training with zero questions about an ankle.
If Polanco were to miss major time with an injury (ankle or otherwise), I believe that he would be the most difficult position player to replace on this team. There are limited options behind him that are clear defensive upgrades, which is concerning given that Polanco ranked last in baseball for Infield Outs Above Average (OAA). Beyond defense, there's only a few players in the league that could match his offensive output at the position.
So what would would the Twins do if Polanco were to go on an extended stay on the Injured List? Below are the internal options to replace him, and they aren't inspiring.
Adrianza is the best fit on the 26-man (that number is still taking a while to get used to) to step in for an injured Polanco. However, Father Time suggests that the 30-year-old Adrianza is not as efficient at the position as he used to be.
Adrianza played 152 innings at shortstop in 2019, down from 534 innings in 2018 due to Polanco playing a full year. Statcast has Adrianza at -2 OAA at shortstop, but he had a 5 OAA in 2018. FanGraphs considered him to below average at the position as well, with a -2 Defensive Runs Saved (DRS) and -14.1 UZR/150 in 2019.
The Twins did not substitute Adrianza for Polanco at shortstop that often in 2019, clearly valuing him more as a utility player at other positions. This is because while Polanco major defensive deficiencies, Adrianza is not that much of a defensive upgrade as a shorstop.
Adrianza did have above average offensive production in 2019, with a 102 Weight Runs Created Plus (wRC+), but Adrianza has previously never posted a wRC+ over 100 during his time at the major league level (career 84 wRC+). Even if Adrianza matches his 2019 offensive production, it would not come close to Polanco's projected 109 wRC+.
Gonzalez has appeared at shortstop more than any other position during his MLB career (292 games), but it's clear the Twins view him more as a utility option at the corners and outfield positions going forward.
Gonzalez started one game at shortstop in 2019, and a whooping two games at second base. The Twins likely took a major note from his last few years playing shortstop in Houston:
2017: -2 OAA, -3 DRS, -8.5 UZR/150
2018: -6 OAA, - 5 DRS, -30.6 UZR/150
Gonzalez would be a fine offensive shortshop, but his defensive ability to field the position no longer makes him an option to fill in for Polanco. He will be a necessary asset to mix-in at first base, where Miguel Sano will be learning a new full-time position, and across the outfield against left-handed pitchers. But he would not be first in-line to replace Polanco if a major injury were to occur, as his days as a shortstop appear to be over.
As I detailed in my Defensive Evaluation post on Arraez, there isn't a large sample on his time at shortstop. However, if there are major concerns with his ability to field second base ( -6 OAA, -8 DRS, -22.6 UZR/150), those worries would be amplified at a much more demanding position.
The vast majority of Arraez's value also comes from his bat, but the water-level of offensive production rises from second base to shortstop.
MLB SS Average in 2019: .264/.323/.439, .321 wOBA, 98 wRC+
MLB 2B Average in 2019: .259/.322/.423, .316 wOBA, 94 wRC+
Luis Arraez in 2019: .334/.399/.439, .360 wOBA, 125 wRC+
Arraez had better offensive metrics than the average at both positions, but moving him to shortstop does reduce a bit of his value as the expectation for production rises. When factoring in the negative defensive value and probable regression, Arraez would likely inch closer to average overall value at shortstop than his primary home at second base.
Nick Gordon is the last infielder on the 40-man roster that can handle the defensive requirements for shortstop, but he is likely a candidate to be removed from the 40-man when Josh Donaldson is formally announced.
In 6 years in the minors, Gordon has failed to show signs of offensive promise outside of a few promising first halves. His collective offensive line is .276/.329/.459 is rather pedestrian for a former first round draft pick, and boosted by an improved showing in 2019 where the ball at the AAA-level was juiced.
When healthy, the Twins played Gordon at shortstop slightly more at shortstop than second base in 2019, with a 40/30 game split between the two positions. The same trend also existed in 2018, with a 69/30 game split. The problem is Gordon has shown durability concerns, likely due to his slight build. This results in extreme production drop-offs in the second half when he isn't missing significant time with an injury.
If Gordon remains on the roster by Opening Day, a Polanco injury might be one of his first and last shots to make an impression on the major league level. All four major league infield positions are locked in for multiple years of control, and more impressive prospects are at lower levels in the system.
While a Polanco injury might be a best-case scenario for Gordon, the odds are stacked against him to provide average-level production as a temporary starting shortstop - let alone coming close to Polanco's offensive level. The impending roster crunch makes it even less likely that an opportunity will arise.
Minor League Signings
The Twins recently signed a few shortstops to minor league contracts, after Ronald Torreyes departed as a minor-league free agent.
Wilfredo Tovar and Jack Reinhemier were signed in December, but both players have limited cameos at the major league level and should be seen as depth "break-glass-in-case-of-emergency" options.
The 28-year-old Tovar has appeared in 40 games since 2013, but the majority (31) came in 2019 with the Los Angels Angels. He has produced a 28 wRC+ and a .217 wOBA in 110 plate appearances, with five extra base hits (all doubles). FanGraphs has rated his 257 career innings at shortstop favorably, with +2 DRS and a 16.2 UZR/150, so his benefit comes from his glove rather than his bat (career .676 OPS in the minors).
Reinhemier is slightly younger at 27, with major league experience with Arizona in 2017 and the Mets in 2018. He collected only 40 plate appearances across these two seasons , with a 23 wRC+ and .196 wOBA. Reinheimer is more of utility player than pure shortstop, as 28 of his career 79.2 MLB innings have been played at the position.
One of these players might be called up as a bench option in the event of a Polanco injury. If they are starting regularly as shortstop, something has gone horribly, horribly wrong.
Why is Polanco the most difficult position player to replace?
The internal options above paint a bleak picture in the scenario of a major Polanco injury. While all other starting position players are all projected to provide multiple wins above replacement, finding a replacement will be easier for all them due to the current layout of the roster.
The Twins have multiple major league caliber outfielders on the bench in the likes of Jake Cave and Marwin Gonzalez. Players on the 40-man that are major league ready, or close to it, include LaMonte Wade Jr, Brent Rooker, and Luke Raley.
The corner infield spots are similarly covered, with Marwin Gonzalez providing positive defensive value (unlike shortstop), and Adrianza right behind him. Even Willians Astudillo and Travis Blankenhorn could provide replacement level service if necessary. Many of these same players could easily step in for Luis Arraez at second base.
The catcher position is also in decent shape, as the Twins will be protective of Mitch Garver with plenty of time given to Alex Avila. Behind Avila, Astudillo is a serviceable (but more entertaining) backup with top catching prospect Ryan Jeffers not too far behind.
All of these positions have stronger backup options than shortstop, where the best replacement appears to be Ehire Adrianza. While Adrianza is a fine utility player, he has never been given a starting role. At 30 years of age, his defense will continue to drop-off, and he is no sure bet to provide above average offensive output as he did in 2019. Without Adrianza's offense making up for his defensive play, as is the case with Polanco, he might become a major liability as a starting shortstop.
There's no near-term replacement for Polanco in the upper levels of the minor leagues, and the major league bench pieces aren't the best fit at his position. As I explained in my earlier defensive evaluation post, Polanco's historical metrics at the position suggest the time to find a long-term replacement is approaching in the next few years. It might be best to have the replacement in the wings, ready to step in in case this horrible game of "What If?" becomes reality.