My personal wish-list would be a controllable CF and good controllable arm rather than a rental. The two names which come to mind right now would be Charlie Blackmon and Tyson Ross. For those two guys, obviously some very good pieces would have to be dealt, but you have control of Ross through the end of 2017 and Blackmon through the end of 2018. Both the Rockies and Padres are not playing great ball and the Rockies may have already conceded the fact they won't be contending this year.