So once they made the decision not to re-sign Papelbon, it triggered a chain of events. The Sox were looking for a closer and made a Reddick-or-Kalish decision on whom to keep as the young OF.
You can't simply look at transactions in a vaccum. So the trade becomes Papelbon and Reddick for Bailey, Sweeney and Ross. Remember, if the Sox didn't trade Reddick, they wouldn't have signed Ross. Ross is the real replacement for Reddick, a right-handed outfielder to platoon in the OF.
So now let's compare:
Ross: 254 PA, 44 R, 16 2B, 16 HR, 50 RBI, .274 BA, .348 OBP, .570 SLG, .917 OPS.
Reddick: 383 PA, 55 R, 16 2B, 21 HR, 46 RBI, .269 BA, .348 OBP, .527 SLG, .875 OPS.
One more stat that I like, Ross has produced 78 runs; Reddick 80 runs. So most of their stats are about equal, although Reddick has about 130 more plate appearances.
Reddick was at the awkward age when the Sox traded him. He had enough of a track record so you kind of knew what kind of player he was. Yet he was also at the age where players sometimes take that next big step. So we'll have to see if Reddick really has made that next step or if he's just a flash in the pan.
One more thing to consider. Ross is doing this in Boston. Reddick might not have the same numbers had he stayed.