Wow, are you serious? For one thing, he has the 7th highest WAR of any CF this year, trailing guys like Hamilton, McCutchen, Trout and Bourn. Fan Graphs has him as the 3rd best defensive CF this year as well, trailing only Bourn and Trout and also ranks in the top ten for .BA and OBP for all CF, his .BABIP is about 30 points lower then his career average which indicates he is getting a bit unlucky at the plate and his average, obp and sulgging should all continue to improve as well. He has the 3rd lowest K rate which is exactly what you want out of a leadoff or #2 hitter type guy, hes going to put the ball in play. Through on top of it that you would have Span for 3+ years and you have yourselves a nice little ball player. Hell I could even see a non contending team like Seattle trading for Span.(Maybe not at the deadline obviously, but heading into next season)