From Baseball Prospectus:
The Report: Graterol got off to a dominant start in the Pensacola rotation before going down with a shoulder impingement. He came back two months later and the Twins moved him to the bullpen for the rest of his season, which included a September cup of coffee with the big club. In the pen he showed an 80-grade sinker that routinely hit triple digits and featured patently unfair movement. There’s a slider that he ramps up into the low 90s and it’s a potential plus-plus offering as well. It’s one of the best two-pitch combos you will find among prospect arms, and there’s only a handful of major league arms who can boast something better.
So there’s going to be a strong temptation to keep Braterol in the bullpen. 2019 only added to a bad injury track record that already includes a Tommy John surgery. However, Graterol is only 21, and he has shown feel for a potentially average change—although one of the three he threw in the majors per Brooks resulted in a very long
Zack Collins home run. He’s not quite as max effort with the delivery as a starter, but it’s not exactly
Greg Maddux either. The Twins have rotation spots to offer in 2020, and I’d be tempted to at least give him a shot firing bullets every fifth day. The upside could be worth it, and hey, that elite reliever fallback isn’t going anywhere.
OFP: 70 / No. 2 starter or elite bullpen arm
Variance: High. The durability track record isn’t good and the reliever risk is significant. —Jeffrey Paternostro
Major league ETA: Debuted in 2019
Mark Barry’s Fantasy Take: As a once silent-cowboy-turned-old-guy-yelling-at-an-empty-chair man once said, “You’ve got to ask yourself one question: Do I feel lucky?” The range of outcomes is huge with Graterol, and the most likely scenario isn’t the most fun for fantasy purposes. Still, his ceiling is so high and the floor (non-injury version) is a very good closer, so he’ll stay in the top-60 or so fairly easily.