In the wake of the (mostly predictable) implosion of Jonathan Sanchez, the Pirates' decision to use Jeanmar Gomez as their fifth starter has worked out brilliantly for them so far, as Gomez has a 2.30 ERA in 11 appearances, including six starts. That includes seven scoreless innings in the Pirates' 1-0 win last night.
The Pirates are taking themselves seriously, though, and they can't let Gomez's recent results distract them from what he is, which is a replacement-level pitcher. Gomez has a 2.30 ERA, but with a 4.27 xFIP. For his career, he has a 4.53 xFIP. If we the Pirates can't identify something in his performance that allows him to consistently outperform his xFIP so dramatically (and they almost certainly can't), then they need to be awake to the possibility of replacing him, 2.30 ERA or no.
So how is Gomez doing it? He's probably benefited more than any other Pirates pitcher from Clint Barmes and the Bucs' infield defense. 57 percent of his balls in play are grounders, and Barmes and co. are gobbling them up. His BABIP this year is just .203, which is a huge credit to the Pirates' infielders, and to the baseball gods in general. They won't keep this up over time. Gomez has pitched better in 2013 than he did in 2012, when he posted a 5.96 ERA, but the biggest difference is that he got some bad luck in 2012, and it's swung way in the other direction this year.
So as good as we feel when Gomez shuts out the Tigers over seven innings, that's not predictive. What's likely to be predictive is his underlying numbers. So the Pirates can't treat him like the guy with the 2.30 ERA. They have to treat him as the guy with the 4.27 xFIP, or the 4.39 SIERA.
That said, what the Pirates should do with that knowledge remains unclear. They may well replace him with Charlie Morton, but that would have to be a decision based on scouting reports -- Morton wasn't that good even pre-injury, and it's not obvious from the numbers that he would be better than Gomez right after returning from Tommy John surgery. Jeff Karstens, Kyle McPherson and Phil Irwin are all hurt. And while Gerrit Cole has the talent to turn his season around quickly, he hasn't pitched so far like he ought to be promoted.
That raises the possibility -- and this is still at least a month or so down the road -- that the Pirates could trade for a starting pitcher. The Pirates, to their credit, have a well-constructed team, but the downside there is that finding where to upgrade is difficult. Right field might be a possibility, and the Pirates will surely look for a bullpen arm or two. But they might get the most bang for their buck by dealing for a starting pitcher and bumping Gomez to the bullpen.