The Red Sox sent Justin Masterson down to AAA Pawtucket, and will eventually replace him in the rotation with Clay Buchholz. Masterson will spend his time in Rhode Island learning the ropes of relief pitching. First baseman Jeff Bailey will be filling in the roster spot until Buchholz is recalled.
I'm not a fan of this move. As desperate as the Sox are for middle-relief, I don't like the idea of sending a prospect like Masterson to AAA in order to convert him into a reliever. He isn't even a fully fledged Major League starter yet. I don't mind giving Buchholz (2-3, 5.53 ERA) another shot at starting, but what if he picks up where he left off? At that point, you don't have much choice but to go back to Masterson. Which means retraining him back into being a starter.
Short term, this is a good move. The Sox NEED help in the bullpen. But they also need starters to go 7 innings consistently. The team can get a good inning out of Delcarmen, or even Okajima. It's when they need to get 2 or 3 innings from the middle-relief that the trouble starts.
To me, the potential damage to Masterson's development is too much of a risk in order to get a new reliever who might not even be a good bullpen pitcher. Long term, this is a bad move.