Tyler Thornburg was solid in his stint with the Brewers in 2013 despite what was a rough start to the season in Nashville. He showcased what is a solid fastball/curveball combination with the occasional change-up. Despite what appears to be a solid repertoire, he will always have an up-hill battle due to his small frame.
Coming in at only 5’11” and 190 lbs, he is far from the prototypical Major League starter. There have long been concerns among the scouting community about his ability to handle a full workload at the Major League level. It has been well-documented that he has a tendency to lose his velocity the later he goes into his starts. Put these two things together and scouts really doubt that Thornburg could remain a starter over the long haul.
Adding to these concerns is his inconsistent command. Last year he posted a BB/9 of 3.51 between AAA Nashville and Milwaukee. Combine that with his natural inclination to allow more home runs due to lack of plane on his fastball and you have a potentially disastrous combination.
There is still hope for Thornburg in the rotation though. Prior to 2013, he had rolled through professional baseball with relative ease. Never posting a FIP above 3.40 at any significant stop, there was reason for the Brewers to be optimistic about his future. Despite his lack of height, he never truly struggled with the gopher ball until this year. He also has shown the ability to strikeout guys at high rates which has allowed him to work around his below average walk rates.
I’m not sure what to make of Thornburg going forward. I struggle to see him as any more than a #3 starter, and that’s the absolute best-case scenario. Most scouts believe he is a reliever, and I tend to agree with them. He could be a back of the rotation starter, but he probably plays best in the bullpen where his stuff can play up, and there is less wear on his body. A guy who sports a mid-90s fastball with two formidable off-speed pitches is a dangerous weapon out of the pen. I see him ending as a very solid set-up guy who can face both LHs and RHs, which is a great weapon for a manger to have late in games.