For half the season, if not more, Mets fans clamored to see Amed Rosario get a promotion to Queens. The Mets’ defense at shortstop was not good and Rosario did a lot of damage offensively in the friendly environment of Las Vegas and the Pacific Coast League. It seemed like the perfect confluence of events. The team’s top prospect performing well at the highest level of the minors, with the club having a need at that very position.
Yet, the Mets refused to call up Rosario until August. Initially, the fans thought the owners were merely being cheap, not wanting to call up Rosario until the nebulous Super Two deadline had passed. For their part, the Mets insisted that had nothing to do with it, that they wanted Rosario to be up for good once they promoted him. The strong inference there was that the player simply wasn’t ready.
Once we got to see Rosario in the majors, it was easy to see both why the fans wanted to see him and why the club thought he wasn’t quite ready for prime time. His speed jumps out at you, especially after watching the mostly-plodding Mets of the recent past. He flies down the basepaths and gets to ball in the field that other club shortstops simply wouldn’t get to. And his bat certainly has some pop in it.
But we’ve also seen a player who takes some curious routes to the ball defensively. And we’ve seen some balls not fielded that perhaps should have been. To be fair, these are minor quibbles and certainly ones that can be addressed and hopefully fixed. But it’s still possible to be better than what the Mets had at the major league level while not being a finished product as a fielder and that seems to be the case with Rosario.
Let’s take a look at some defensive numbers for the Mets’ three primary shortstops here in 2017 so far this year:
Reyes seemed like a defensive upgrade from Cabrera but the numbers don’t view that as a slam dunk. If they played similar innings at their established seasonal rate, the DRS for the two would have been very close. But on the UZR/150 scale, Reyes was considerably worse. But Rosario has been better than both of his predecessors regardless of which metric you prefer.
Sure, the club needed a defensive upgrade at short. But what had most fans excited about Rosario was his offensive potential. And the early numbers again bear out what the Mets were saying, in that Rosario still had work to do when the fanbase wanted him up in the majors in late April.
One of the stated goals for Rosario was to improve his plate discipline. And after 145 PA in the majors, he has just 3 BB compared to 40 Ks. There’s no way to describe a 2.1 BB% and a 27.6 K% as anything else but ugly. Why any pitcher throws him a strike at this point is up for debate. Rosario has a 45.9 O-Swing%, meaning he’s hacking away at nearly half of the pitches he sees that are balls.
It may be hard to immediately recognize how bad that is. Of the 432 players who’ve had at least 100 PA in the majors so far this season, Rosario has the third-worst O-Swing%. The two guys who have worse O-Swing% numbers are Salvador Perez and Jorge Alfaro. Those guys just like to swing, period. Meanwhile, Rosario has just a 66.3 Z-Swing%, which ranks tied for 246th-highest in the majors, or in the bottom 50 percent of the league among those with at least 100 PA.
He needs to do a better job of identifying which pitches to pull the trigger and swing.
Rosario has a healthy .344 BABIP yet just a .697 OPS. Because of his ability to beat out infield hits and to make solid contact when he does connect with the ball, we would expect Rosario to post higher-than-normal BABIPs. Perhaps not .344 high but certainly above the traditional .300 mark. So we have a case here of the hits falling in – at least some – yet the overall numbers not being acceptable. And the primary culprit is the strikeouts.
This year in Las Vegas, Rosario had a 5.4 BB% and a 15.8 K%. You’d definitely like to see more walks but that strikeout number doesn’t look bad at all. But Rosario got slightly worse in this regard as the season went on. Through the first 44 games, he had a 13.3 K%. Then in his final 50 games, that number climbed to 17.8% and we see what’s happened once he’s reached the majors.
The Mets are committed to Rosario at shortstop in 2018 and beyond. Most of us imagine that we’ll be very happy with that arrangement. We look forward to seeing him fly around the bases and also adding to his already-displayed power numbers. In some ways, the potential seems unlimited. Yet, if Rosario doesn’t improve his plate discipline, he’ll never come close to reaching his potential.