There was no reason to think he's better than someone like Lovelady though. We're talking about fungible replacement-level arms. Yarbrough is terrible, and throws 86 so he's always going to be terrible. Lovelady is terrible, but the team might think he has a chance to not be terrible because they see something in his sinker/slider combo. If they're wrong and he stays terrible, he'll be cast aside and the next gas can with an interesting pitch mix will get called up.
The bullpen is atrocious, but it wouldn't be any better if 34-year old Ryan Yarbrough were here chucking 86-mph slop.