There are two sides to the news that Didi Gregorius left the World Baseball Classic early because of a hematoma of the subcapsular muscle: on one hand, Gregorius is one of the best position players on this team, to the tune of 5.8 fWAR over the last two seasons.
On the other hand, as Harlan Spence so eloquently put it in the comments of that article, if Gregorius “was going to be one of their 2-3 most valuable players again, then they were going to be bad.” That very well may be true.
But that doesn’t mean he isn’t important, and it doesn’t mean this could send reverberations throughout the roster. In all likelihood, this isn’t a huge deal. This is just a bruise after all, but you just never know; sometimes these things can linger.
If for some reason Gregorius’ return is delayed more than the two weeks or so until Opening Day, here’s what could happen. First off, it means Ronald Torreyes is a lock for the 25-man roster, as he can back up both shortstop and second base.
Rob Refsnyder could very well make the team too, and he would be the de facto backup at second base. In that world, there’d be a revolving infield of either Starlin Castro or Torreyes at shortstop, and Castro, Torreyes, or Refsnyder at second base. There’s also the outside chance that Tyler Wade makes the team, but that remains to be seen.
In terms of actual value... that’s unclear. By Steamer, Gregorius is a 2.3 win player per 600 plate appearances, give or take a half win. If he were to miss 100 plate appearances, so about a month, an actual replacement player in his place means the Yankees would lose about .38 wins, so let’s just say a third of a win.
In all likelihood, this is statistical noise. A third of a win, or even two-thirds of a win if he were to miss two months, is essentially nothing; good or bad batted luck, or one single game swinging your way when it shouldn’t, wipes that clean.
Conversely, though, the Yankees can’t really afford to lose anything. If the team is to contend at all, pretty much everything has to swing right. Harlan is right that if they are to contend then Aaron Judge, Gary Sanchez, and Greg Bird have to exceed expectations, but in the case where they’re about as good as expected, then all the other factors—injuries, pitching staying intact, the bullpen staying dominant—have to also fall into place.
It’s still very early, so there isn’t a need to hyperventilate about what amounts to, as I said, a bad bruise. However, in a perfect 2017, bad bruises are avoided. In a perfect 2017, this ends in a few days and doesn’t, as it can tend to do, stretch out into weeks and months.
While Gregorius isn’t make-or-break if the Yankees truly intend to be great, but it’s, in the wise words of Joe Girardi, not what you want. Aside from the performance itself, it would still hurt to lose one of the Yankees’ brightest personalities of this team over the past few years.