What happens when an already weak bullpen suffers a rash of injuries? They get fill-ins who didn’t make the major league roster in the first place, of course. The Houston Astros have realized that problem this season. Just after the season started they lost Sammy Gervacio to the DL. Tim Byrdak followed, as did Chris Sampson. Brian Moehler had to take a spot in the rotation because Bud Norris hit the DL. Even Matt Lindstrom missed time not long ago with back spasms. There wasn’t much downside to these loss, however, because aside from Lindstrom none of them were effective. The minor league replacements probably couldn’t do any worse.
In the process of replacing their injured relievers, the Astros actually found two upgrades. Both Gustavo Chacin and Wilton Lopez have pitched very well out of the pen, and have probably earned regular spots even when the wounded return from the disabled list. That might make for a few unpleasant roster cuts, but at this point the Astros have little to lose. The relievers who broke camp with the team likely won’t be around when the Astros turn around the franchise, so it’s best now to stick with the guys who are performing. Chacin and Lopez are doing exactly that.
Lopez gets most of the spotlight, and rightly so. Recalled after Gervacio’s initial injury, Lopez stumbled out of the gate, allowing two runs on three hits, including a home run, in 1.1 innings. He allowed a run in his next appearance, but, despite pitching three scoreless innings in his next two appearances, the Astros optioned him in late April. But after Byrdak got hurt in early May, the Astros invoked the Ten Day Rule and brought Lopez back to the major league team. Again he stumbled, allowing four runs in his first three appearances, but since then he has been nothing but stellar for the ‘Stros.
From May 18 through his appearance last night in Milwaukee, Lopez has allowed just six runs, five earned, in 20.2 innings. He doesn’t do this by overpowering pitchers. Instead he does two things very well. First, he keeps the ball in the park. Second, he walks almost no one. During his stay in the minors he walked just 1.2 batters per nine innings. This year he was walked just three in 30.2 innings, a BB/9 under 1.00. That helps make up for his lack of strikeouts.
Chacin had a four-year history in the majors before coming to the Astros this off-season. He came up with the Blue Jays in 2004, and pitched very well in 2005, a 3.72 ERA in 203 innings. That outperformed his peripherals a bit, so a correction was expected in 2006. Instead what we got was a series of injuries that prevented Chacin from doing much of anything in the following four years. After pitching 87.1 innings in 2006 and 27.1 innings in 2007, Chacin missed all of the following two seasons. He did pitch well for the Phillies in the minors in 2009, but could not crack the major league roster.
Yet this year Chacin has been marvelous. He’s pitched just 17.2 innings since his recall in early May, but he has not only shown excellent results, but also the peripherals to go along with them. His strikeout rate has risen dramatically, to 8.15, and he hasn’t allowed a home run all season. Of course, in 17.2 innings anything can happen, and the safe bet is for Chacin’s home run and strikeout rates to tumble a bit before the season ends. Yet if he keeps up his current trend of striking out lefties (10 of 32 faced) and inducing ground balls against righties (19 of 39 balls in play), he might continue to find some level of success out of the pen.
The one area where Chacin and Lopez have differed is in their ability to prevent inherited runners from scoring. Chacin has inherited 16 runners and has allowed seven to score, 44 percent. That matches Tyler Clippard‘s rate, for comparison’s sake. Lopez, on the other hand, has excelled in this area. He has come into pitch with 22 runners on base, and has allowed just one of them to score. So while Chacin has the better rate stats (3.06 ERA, 2.51 FIP vs Lopez’s 3.52, 2.97), Lopez’s performance stands above Chacin’s because of his ability to pitch with runners on base. For a bullpen that allows a ton of baserunners, Lopez has been a boon.
Relief pitchers, we know, tend to realize inconsistent results. They pitch in such short bursts that the random nature of baseball works against them just as sometimes it works in their favor. It’s no guarantee that either Lopez or Chacin continues this performance throughout the season, never mind both of them. But in the moment they’re helping out not only an ailing relief corps, but also an ineffective one. With Chacin and Lopez pitching behind Lindstrom and Brandon Lyon, the Astros have a little hope for victory when their starters leave with a lead. It won’t vault them into contention, but it will at least help them win a few games that their original bullpen would otherwise have blown.