We’ve known since opening day that Jeff Suppan, against all of many fans’ best wishes, would be activated today to start today’s game against the Cubs. The only question was who would be sent down in order to make room for Suppan – only two pitchers on the Brewers roster still had options remaining: Carlos Villanueva and Mitch Stetter.
The Brewers sent Stetter down, and I believe that is easily the correct choice. Holding three lefties in the bullpen is redundant, but really, Stetter just isn’t that good. Stetter is utterly incapable of facing Major League right handers – he’s allowed a 5.56 FIP over his career to right handed batters. That means he’s really only useful in an appearance against one left handed batter. In order to be worth using that roster spot on a true LOOGY – Lefty One Out GuY – he should absolutely dominate against lefties. He hasn’t – a 3.27 FIP is respectable, but not fantastic.
The Brewers already have two other lefties in their bullpen: Manny Parra and Chris Narveson. Parra has a 3.69 FIP against lefties, but that comes almost entirely in a starter’s role. Given that relievers only face the lineup once and are able to reach back for extra velocity on a regular basis, Parra’s FIP against lefties in a relief role would probably fall below 3.00. Parra also has a much better FIP against righties, at 4.68. He would not have to be a one-out reliever, and could easily pitch against players of both hands and even pitch multiple innings. We don’t have quite as much data on Narveson, but he has similar splits to Parra so far in what has been a mixed career between starting and relieving. Both pitchers have changeups, which explains how they can at least partially neutralize left handed batters.
Carlos Villanueva’s numbers don’t look particularly impressive – his last 3 FIPs are 4.80, 4.49, and 4.28, all poor numbers for a reliever. However, Villanueva has simply been awful as a starter, posting -0.5 WAR as starter in 48 innings. I’m not completely ready to give up on him in that role, but the Brewers obviously have. Regardless, he’s been very successful as a reliever, posting about 1.5 WAR as a reliever the last two seasons. Villanueva also doesn’t have much of an obvious platoon split, making him a good option against a mixed lineup.
Overall, I think that using Parra and Narveson as the pitchers against lefties will be sufficient, and Villanueva is simply too good at his job to send him down. Stetter is a fun pitcher to watch, but simply isn’t talented enough to warrant kicking anybody else off the time. Of course, the best option would be for Suppan to just go away, but unfortunately Brewers management is just not allowing that to be an option right now.