Yankees Potential Free Agent Target: Marcus Semien

There are reports that the Yankees are no closer to a deal to keep DJ LeMahieu in the Bronx, which leads one to speculate on the various avenues the team could pursue to replace him if he signs elsewhere. On Friday, I detailed a glove-first fill-in for LeMahieu in Andrelton Simmons. Today I’d like to look at Marcus Semien, a player who gave us a taste of an offensive ceiling far higher than anything Simmons could muster.

Semien is probably the most perplexing high-profile target on the position player free agent market. While he did flash a glimpse of MVP-caliber offensive talent, the problem is it was just that: a glimpse. In every other season, he has been a below-average hitter. So how are we to square his performance in 2019 with the rest of his career?

First, let’s recap the offensive breakout that earned him a third-place MVP finish two seasons ago. That year, he appeared in all 162 games, batting .285/.369/.522 with 33 home runs, 92 RBIs, a 139 OPS+ and 137 wRC+. He established himself as one of the premier slugging shortstops in the game, perhaps setting himself up to be the crown jewel of the current offseason, hitting the market a year before the shortstop bonanza of 2022. Unfortunately, he crashed back to Earth in 2020, likely jeopardizing any chance at a nine-figure payday this winter.

So the big question is: which version of Marcus Semien can teams expect going forward, the 2019 superstar or the middle-of-the-road bat in all other seasons? Craig Edwards of FanGraphs penned a thoughtful analysis of why 2021 can be a resurgent campaign for Semien, with much of his case built on Semien being doomed by small sample size in 2020. I however am not as bullish on his prospects and lean more towards his 2019 being somewhat flukey.

Oh. In addition to the giant leap in the batted ball department, Semien also posted career-bests in strikeout rate (13.7%) and whiff rate (18.3%) before they promptly returned to his average from all other seasons (21.2% and 23.3% respectively in 2020). That he reached such astronomical heights in nearly every offensive category in 2019 and then regressed right back to his career norms smells fishy to me.

Edwards pointed out that a late push down the stretch rescued his season numbers. And if we include his postseason masterclass, he would have finished with a 106 wRC+ and 1.8 WAR (4.8 fWAR pace). However, the mechanisms that underlay these improvements do not give me as much confidence. Semien’s average exit velocity remained flat throughout the regular season and playoffs, and it was only when he started lifting the ball more that he saw his fortunes turn. That his upturn was not accompanied by an increase in hard hit balls suggests to me that the results are less likely to carry into the future.

How is it that Semien ceded the roughly two miles per hour of exit velocity gain he made in 2019? Perhaps he benefitted, like many others, from the 2019 rabbit ball. Or perhaps it was due to mechanical flaws. In any case, a large culprit was his performance against the fastball. He absolutely punished fastballs in 2019, to the tune of 26 home runs and a +16 run value according to Statcast. That disappeared in 2020, when he mustered only three dingers and a negative run value.

Here we see Semien facing the same pitcher, throwing the same pitch in the same count. The top is from 2019 and the bottom from 2020. I have to thank my colleague Cooper Halpern for his insight into how to interpret what I am seeing, as well as his help with piecing together the many aspects of this puzzle. You can see in 2019 how fluid and uninterrupted his load is to create separation. However, in 2020 he at times had an extra hitch in his load, creating a more herky-jerky movement. This double load breaks the momentum of his hands, and the stop-start-stop-start action resulted in him being late on the fastball.

Taking a look at his defense, Semien has posted a +21 DRS and 17.1 UZR at short over the last three seasons. These (relatively) older sabermetric measures give the impression that Semien is an above-average shortstop. However, Outs Above Average paints a less rosy picture, unclouding the circumstances that artificially inflate his other defensive metrics. Semien oscillated between a -4 OAA and -3 OAA since the stat’s inception in 2017.

This is because he has benefited from sharing the infield with two Gold Glovers. Matt Chapman’s ridiculous range means Semien has to cover far less ground to his right than the average shortstop, while Matt Olson’s crazy picking skills at first have spared Semien on many a poor throw. In any case, he still would be far less a liability at short than the incumbent, allowing Gleyber Torres to shift back to second base.

But Peter, you might ask, why would the Yankees be interested in Semien if he is more likely to be below-average than great? You’re right, odds are Semien does not reclaim the heights of season before last. Which is why I am inclined to suggest that the Yankees take a hard look at him if LeMahieu does not return.

Semien’s value is not likely to be lower coming off a down 2020, not while shortstop-needy teams can simply wait another year to sign one of the quintet of younger, better stars hitting the market. If Semien rediscovers his 2019 form, he could be the bargain of the offseason. FanGraphs has him pegged at three years and $51 million while MLB Trade Rumors is far less optimistic, predicting a one year $14 million pact. Both would be absolute steals should he have another 2019-esque, 7.6 fWAR season in him, even if the odds of him doing so are unfavorable.

From everything we’ve discussed, it appears that 2019 was an outlier season for Marcus Semien. But I can’t seem to shake the notion that he still has a lot to give. To steal a quote from Cooper: There’s a good player inside of Semien. I have no clue as to whether we’ll ever see him again. Still, it would behoove the Yankees to buy a lottery ticket on the veteran shortstop if LeMahieu does not re-sign, since there is still a chance they could hit the jackpot.