If the Braves are more pessimistic about his future they could see it as an opportunity to maximize their value(prices are higher at the deadline too), they've never been huge cheerleaders of Teheran anyway. At AAA and above alone they have Dickey, Garcia, Colon, Folty, Wisler, Newcomb, and Sims so they wouldn't be creating a hole(the idea isn't 'oh man we have to trade someone now to make room'). No one's saying that you get Teheran by trading Zagunis and Justin Steele and calling it a day, but relative to other guys who the Cubs might peg to similar future values he could be available(an increasing problem given everyone in the AL is 2 games out of the wild card) and less expensive.