Even before the injury to Joel Zumaya, the Tiger bullpen, which deserves a large portion of the credit for how well the team has performed thus far, was likely to see some regression. They rank third in the American League in bullpen ERA, but Expected Fielding Independent Pitching, xFIP, ranks them in the bottom third. This is primarily due to their third-to-last strikeout to walk ratio, their league low home run per fly ball ratio, and third best batting average on balls in play (BABIP).
The xFIP calculation assumes (and rightly so) that if you walk too many hitters, and don’t strike out enough, you’ll get bit more often than not. It also assumes that a certain percentage of fly balls will inevitably clear the fence and a certain percentage of batted balls will end up as hits (some would say Tiger relievers have been “lucky” on fly balls and balls in play). I wouldn’t say that the performance of the bullpen so far has been all smoke and mirrors, but there’s definitively been a little smoke.
Now it appears that the Tigers will be without Joel Zumaya for a while, probably the rest of the year (my guess, we’re still waiting for an official report). This leaves Jose Valverde as the lone man in the bullpen with an xFIP south of 4.50. Phil Coke has done well getting Zumaya and Valverde the ball in the late innings, but I’m not sure I’m comfortable with him being “the guy” in the eighth inning. Eddie Bonine’s numbers are being puffed up by an unsustainably low 0.216 BABIP, and Fu-Te Ni and Brad Thomas have shown no ability to prevent runners from reaching base.
It will be a big boost if Ryan Perry can eventually return from the disabled list healthy, but the team may still need to pilfer a reliable arm (or two) out of the minor leagues. I’m not quite sure if there’s a guy that’s ready to take on late innings in the Major Leagues right now, but they may need to force an inexperienced arm into that role. Casey Fien will be getting the call to the big leagues for now; it will be interesting to see what role he’ll play out of the pen.
After the five out save last night, Jim Leyland said he won’t make Valverde available to pitch tonight, so the Tigers’ will be without their closer and primary setup man.