I agree on dealing Rivera. He's one of my all-time favorite players, but I am almost sure the Yanks are going to want to use him a lot left after a less-than-perfect postseason (caused by too much work in my opinion). That along with the slight arm trouble this spring means he's going to see less action. Throw in Crosby and find someone who will overpay for him with a strong SS.
See if you can pick up another RP off the waiver or get a not as big time one for Gagne along with some other help. That trade for Santana might be an option but I wouldn't deal Perez so quickly if you can avoid it. Go for upgrading your SP and SS.
Nice team overall though.
Let me know what you think of my team:
http://www.fantasybaseballcafe.com/forums/viewtopic.php?t=105281