In dire need of arms that could give length, the Phillies claimed Dylan Covey off of waivers from the Los Angeles Dodgers in May. Covey got on the bad side of Phillies fans very early when he imploded in a Sunday night game against the Braves, allowing seven runs (five earned) while only recording two outs. This would be his only start of the season. He'd pitch exclusively in low-leverage the rest of the way and looked quite good.
Covey made 28 appearances for the Phillies, posting a 3.69 ERA in 39 innings of work. If you look at his body of work after the Atlanta game, Covey had a 2.70 ERA in 26 appearances. There really wasn't anything wrong with him, but there are a couple of reasons why Philadelphia might want to part ways.
First, he's arbitration-eligible, meaning he's going to make more than just the league minimum. He won't make a lot, but he'll make more than the minimum. Second, and most importantly, he's out of options. This really hampers Philadelphia's flexibility when it comes to bullpen management, as he can't be sent down without going through waivers. That's why he remained with the team from the moment they signed him until the moment he landed on the IL in September.
Covey pitched well for the Phillies but still has a 6.18 career ERA in 100 appearances (48 starts). He's been given countless opportunities and for the most part, has done nothing with them. The Phillies expecting a repeat of the year he just had would probably be foolish.
The Phillies can easily find someone with Covey's track record that they can bring in with options on a minimum deal. He didn't perform as poorly as a guy like Jake Cave, but the lack of options really is a killer here.