Not so much an analysis as a quick observation -
There was some concern tonight regarding RRS' fastball, as out of his 19 heaters he never once broke 88.4mph and only twice broke 87. Such concern is warranted, since RRS usually works in the 87-90 range and has a season average around 88. Velocity drops are never a good thing, and tonight RRS was exceptionally low:
The chart shows RRS' average fastball velocity by 2008 appearance. You can see that his velocity tonight was the lowest it's been all year. That one point above 91, by the way, was from the outing against the Angels where he was called on to retire Garret Anderson to end the game, and during that appearance RRS threw but a single adrenaline-loaded fastball, so you should probably consider that point an anomaly.
What was the matter tonight? I'm not sure. Maybe it was the rain. But gun to my head, I'd guess that it has something to do with this being RRS' sixth appearance in ten days. After being invisible for much of April, RRS has seen a lot more action in May - the most frequent action in his career. Wouldn't surprise me if he's wearing down a bit under the burden. Warming up and getting game action that often is bound to take its toll on someone whose body is unaccustomed to such repeated stress.
Hopefully the starting rotation is able to give RRS a bit of a breather in the coming days, and tonight turns out to be little more than a fluke. But this is something to keep an eye on. Sustained velocity drops are always bad. Should this keep up, then it's a problem.
By the way, that dotted line in the chart? That's RRS' average fastball a year ago. So far in 2008 he's down ~2mph. He's only exceeded last year's average on one occasion, and that was during the one-fastball Angels game. So that's a little disconcerting. Might (might) have something to do with his playing winter ball in Venezuela, but that's just a shot in the dark. Mitigating my concern, however, is the fact that, at least thus far, the velocity drop hasn't hurt his performance. His command's been a little off, but he's never had pinpoint location, and he's getting more swinging strikes now than he was last summer (19% to 17%). So if the data's correct and he really has lost a couple miles, he seems to have figured out a way to get by no worse for wear.