Here's one out of left field. Hisashi Iwakuma has been placed on the 15-day DL with a right lat strain, retroactive to 4/21. There's no telling when he injured it, or how long it's been bothering him. If it dates back a bit, there's your aha moment for his struggles.
No word on who's coming up to replace Iwakuma, but it seems fairly obvious it will be Roenis Elias. In the mean time, Lucas Luetge will come up to help in the bullpen until they need Iwakuma's turn, which is scheduled to be Sunday afternoon.