-P- The Pirates get Rodriguez and cash to pay part of the money remaining on his contract. The Bucs will pay $1.7 million in 2012, $8.5 million in 2013 and $7.5 million in 2014. (Rodriguez has a player option in 2014 that he will probably exercise.)
-P- The Astros get outfield prospect Robbie Grossman and pitching prospects Rudy Owens and Colton Cain. (Grossman and Cain are from Texas, incidentally.)
-P- The Pirates will likely remove Kevin Correia from their rotation to make way for Rodriguez.
Rodriguez is a big upgrade for a Pirates' rotation that has, at times, looked shaky after James McDonald and A.J. Burnett. Correia has a horrible strikeout rate of 4.05 batters per nine innings (bolstered, admittedly, by a couple recent starts in which he struck out many more batters than usual) and isn't a great bet to hold up down the stretch.
Rodriguez, meanwhile, hasn't had a bad season since 2006. Like many lefty starters, his velocity isn't overwhelming (his fastball typically comes in at around 89 MPH). But he bolsters his fastball with a curveball that can often be filthy. This year, he's striking out fewer batters than he used to, probably in part because his curveball breaks a bit less than it used to, but he's also walking fewer batters -- perhaps, again, in part because his curveball doesn't break as much. In any case, he's still effective as a third-starter type, and he just get a boost in his bid to remain so as he moves from an awful pitcher's park in Houston to a good one in Pittsburgh.
Not only can Rodriguez help the Pirates down the stretch, but he can also help them in 2013 and perhaps 2014. Correia and Erik Bedard are free agents after this season, and Charlie Morton isn't likely to help next year either, if he's even still in the organization. Rodriguez gives the Pirates more certainty about their rotation picture in 2013, which is good, because it wasn't clear who they were going to use beyond James McDonald, A.J. Burnett and probably Jeff Karstens. The $7.5 million the Pirates will owe Rodriguez in 2014 presents a little more risk, but it's worth it, given how helpful he can be in 2012 and 2013.
Grossman, Owens and Cain are, at least from this outsider's perspective, exactly the sorts of players the Pirates should be giving up in trades like these. They've all had their moments in the minors, but scouts aren't enamored with any of them.
Grossman is the most valuable of the three, and he attracted notice after a 2011 campaign in Class A+ Bradenton in which he walked 104 times. The point of minor-league baseball, however, isn't to put up freaky-looking stat lines, but to prepare for the majors, and that's where Grossman doesn't quite do it for me. Unless he dramatically improves at hitting for average and power (and he's made clear strides in those areas, but he's still not great at either of them), I don't think he'll be able to put up huge walk totals in the majors, where he'll regularly face pitchers who have good command. He'll have to continue to improve as a hitter to have much of a career. He might just do it, but since he's likely going to be a corner outfielder in the majors, he'll need to hit quite well to be effective, and I can see why the Pirates might be betting against him.
Owens and Cain, meanwhile, profile as back-of-the-rotation starters, and that description might even be overly generous to Cain. Owens will likely have some sort of career as a fourth or fifth starter. That sort of player has value, but it's also the sort of player the Pirates should be able to find on the free agent market. Rodriguez is better than that.
This is a risky deal for the Pirates, but it's a solid gamble on their part. As they head toward the trading deadline, the Bucs will likely turn their attention toward finding an outfielder. The fact that they're only paying Rodriguez $1.7 million this season may give the Pirates the financial flexibility they need to swing another deal.