Is he any good? per overthemonster
"It’s hard to say for sure, owing to the fact that he doesn’t have much of a track record yet, but he looks promising. Campbell has pitched just 28.2 Major League innings in his career, having made his debut last July. Prior to that, he was a four-year college pitcher who missed significant time due to Tommy John surgery, and then spent an additional two-and-a-half years in the minors, so it’s not like he’s some young phenom (he’ll be 26 on Opening Day).
But having said that, the 28.2 innings he pitched last year were pretty good ones. He gave up just two homers and struck out 33 hitters while posting a 2.83 ERA. He throws a mid-90s fastball, a slider, and a sweeper, with the slider being a very effective wipeout pitch that yielded just a .137 batting average and .157 slugging percentage against. Where he struggled last year was with control, as he walked over four batters-per-nine-innings. But what’s notable about that number is that it represented a marked jump from his time in the minors, where he kept that number down to 2.5 over the course of 89.1 innings. If he can figure out how to keep getting hitters out while limiting the free passes, he can turn into a very effective late-inning reliever for the foreseeable future"
Lots of ifs but maybe promising. Still need another lefthander in the pen.