Years ago I used to get really annoyed when I would read somewhere that Tyler Thornburg was going to be a reliever. He was starting in the minors and doing well! So what if his command wasn't great and his height made it hard for him to get downward plane on his pitches? Well it turns out those scouts and evaluators were correct. I've learned a lot about propsects and baseball since then. But now I still get annoyed when people say Thornburg isn't a major league caliber player at all. Time will tell if I'm right on this account or if I'll learn something else over the next couple of years.
Thornburg is not without risk, but I want to address the positives first. He has solid velocity on his fastball which sits around 92-94 mph. He also has two other usable pitches: curveball and changeup. That's a starters arsenal. And in a bullpen role, it should play up. But it hasn't really done that yet. He does have a career 3.13 ERA at the major league level. But his 4.27 FIP suggests he's not been that effective.
His two main problems at the major league level have been injuries and walks. The former perhaps being the cause of some of his more absurd numbers (16.0 BB% rate in 2014, 1.83 HR/9 last year). Outside of 2014 his walk rate hasn't been horrible--not exactly good either. And outside of 2015 his HR/9 has actually been really good.
In 2014 Thornburg dealt with injuries that severely limited his playing time. Outside of two outings in June he didn't pitch at all. Later that year he would have a PRP injection to help him cope with a partially torn elbow ligament. Often that type of injury requires Tommy John surgery--which is a bigger deal than I think people tend to think these days. He spent the offseason rehabbing and returned to action in April, for a time.
He struggled early last year and ultimately was sent back to AAA. He was even worse there logging a 5.28 ERA and 5.91 FIP in 88.2 innings across 17 starts. I think that's why a lot of people gave up on him--even though we all know the difficulties in pitching at Colorado Springs.
He returned to the major league squad at the end of July. And from that point on he pitched to a more reasonable 2.92 ERA and 4.47 FIP. Home runs were still a problem for him though as he allowed 1.46 HR/9. But he also struck out 26% of batters faced which is really good.
I still believe that a healthy Tyler Thornburg will be an effective Tyler Thornburg. But at this point health must be considered a major concern. I don't know much about PRP injections and their success rate. I'm not sure anyone does at this stage. So Tommy John surgery may still be a thing that happens for him. If it's not and injuries abate, I'm excited about his potential. So I'll just be over here hoping for the best.
Statistics courtesy of FanGraphs