Why not? Because he's not expensive, he's a league-average player, there's nobody waiting at the gates internally to take his roster spot, and he's not here long-term anyway? What's the upside to keeping him, though? I couldn't care less either way whether he was traded in a Jose Ceda type deal or he stuck around. One less roster spot to have to fill, basically. Jackson and Byrd can play CF/RF without hindering Jackson's progress if he's ready. The Cubs already need to find a SP or two and a quality 1B (and likely a 3B).