It's hard to trade him because of his contract. It's his fault or agents fault for signing with an aging team.

That and closers tend to have short shelf lives.

He's much more likely to be traded this off season or next year if he will waive his vesting option for 2016, which I doubt he's going to be willing to do unless he feels like his market is going to be worth more than 13M, which I highly doubt.

In other words, he's probably stuck in Philadelphia for the next couple of years.