He can't really mop-up because like Andy says he doesn't have length, but they have Ross for the next 10 days if there are no other moves, and Alvarado's return pushes Banks (who can give more length) down too.
He only pitches in losses or blowouts for the most part already. His last three outings (two of which were bad) he entered when Phillies trailed 4-0, trailed 2-0 and led 7-1. He actually kept them in the 2-0 game and stunk in the 4-0 game. The three before that he pitched well while the Phillies were trailing 7-5, 5-1 and 1-0 (he got the win in that one when they scored four runs the next inning). At this point he's not our failed expensive closer, he's just Dylan Covey but not suited for that role.