Drew Smyly has had a fantastic year out of the Tigers bullpen. That’s hard to argue. He’s thrown 69 innings, turned in a 2.22 ERA and 2.43 FIP (what’s FIP?) to go along with a 1.5 WAR (what’s WAR?). He has struck out 26% of opposing hitters and walked just 5.5%. He’s been otherworldly against lefties and pretty good against righties. In fact, until August, he was dominating righties as well.

In August, Smyly had a rough go of it. It was only 8 innings and 35 batters, but it wasn’t good. It was the equivalent of one or two really bad starts, but for a reliever it looks worse. But even after that rough August, our own reliever metric, SOEFA, still likes him as the 11th best reliever in the game this year. So let’s take a look at his monthly splits and see if there is anything we should worry about going into October:

So while it is only 8 innings, the ERA is way up, the average is way up, the OBP is way up, the slugging is way up, and the wOBA is way up. Hitters did a lot better in August.

Smyly struck out fewer batters in August, but he also walked almost no one. You’ll notice a much higher BABIP and a clear spike in FIP. His xFIP (what’s xFIP?) goes up as well, but not nearly as much, which tells you that homeruns were likely a bit of an issue in August.

Smyly gave up three big longballs in August after allowing just one all season long prior to that. That’s going to drive bad results over 8 innings. This is a small sample, clearly, but the exercise is useful in pointing out that Smyly hasn’t performed well lately. Is this cause for concern?

Using Brooks Baseball’s Pitch F/X data on his fourseam fastball, we observe this pattern in game to game average velo:

The average climbed until his 30th or so appearance and has been working its way down a bit since then, but there is a lot of fluctuation. There is a trend over the last dozen appearances, but not really as much over the whole season. The movement, which is a little harder to show graphically isn’t quite as crisp as his best days, but it’s not dramatically different. His release point is drifting very marginally toward the center of the plate, but again, not in a big way.

It just looks like he threw a bad pitch to Konerko and Moss and Salvador Perez hit a good one. That’s really the difference between a good month and a bad one for a reliever who only saw 8 innings. If there are signs of fatigue or an injury, they aren’t big, dramatic, and clear signs.

This doesn’t look like anything to worry about. Some are concerned about his workload based on his never having pitch out of the pen like this, but he threw 100 MLB innings last season and isn’t getting anywhere close to that in 2013 and is still 700 pitches or so behind the number he threw last year.

This appears to be a blip on the radar for Smyly who continues to be having a great season overall. Leyland appears to watching him closely and has gone five days without using him at this point. I’m not sure if that’s a good strategy or not. I think I would want him to get more regular reps down the stretch, but it’s possible he’s tiring a bit and Leyland knows something we don’t. Either way, nothing I’m seeing concerns me very much about Smyly and I expect he’ll be one of the best relievers in baseball the rest of the way.