This is a tough one. Cabby has been a good player for the Rays to have because of his ability to play almost every position and his bat being generally productive all year. He's likely to end the season as a 2.5 fWAR utility player who gets a significant portion of his value from defense. That impressive. I also think there's a better than average chance Rainer is moved to 3B given his arm (excellent) and fielding (average) grades. The Rays of course should have no need for a top 3B prospect anytime soon with JC manning the position right now. Of course, that's what we said about SS a few years ago, and look at us now... In the end, I'd probably do this trade at the Deadline if the Rays elect to sell. You should never pass on trading a utility player for a potential starter with a big bat.