As has the thumb injury right? My guess is if hendricks was healthy jake would sit for a couple of weeks and let it heal but with butler and montgomeey already in the rotation and Lackey a piece of horsefeathers he is trying to grind it out or something. Has it been going on all year? I wasn't sure. If so, that might be a good explanation. If he was able to hold up for a whole 7 innings his last start, maintain his velocity, pitch decently, and didn't have problems with the thumb, then maybe it is just the thumb. And it would make sense, because the thumb thing would pop up in the middle of the start.