Other than a truly elite groundball rate (over 62% as a pro) and a frame (6-foot-6, 240 pounds) that should allow him to chew up innings, there is not a ton to get excited about with Peterson at first glance. The big lefty commands a four-pitch mix, with his heavy, low-90s fastball and above-average slider grading out as his two best offerings. A knee injury cost him a few weeks early in the year, but he still amassed 128 frames. Over his final five starts, he gave up two runs, allowed 21 baserunners and struck out 32 over 29 innings. His groundball rate was also a ridiculous 71% over that stretch. That success in a small sample might mean nothing. After all, he was a 22-year-old southpaw with command and pitchability facing High-A hitters at the end of a long season. However, if he somehow maintains that late-season strikeout rate at Double-A, it would warrant quick action in dynasty leagues, as his ability to generate weak contact is already outstanding.

A big 6-foot-6 southpaw, Peterson has the potential to have three above-average pitches and and above-average command down the road, hinting at a future role as a No. 4 starter. His low-90s fastball isn't much of a bat-misser, but he should excel at generating groundballs. His slider and changeup both have the potential generate whiffs, and while neither is a plus pitch right now, both have a chance to get there. The key for Peterson will be carrying over the excellent control he showed in his junior season at Oregon, where he posted a 1.4 BB/9. Surgery to remove an ingrown toenail limited him to just three starts for a total of just 3.2 innings in his pro debut. He is advanced enough to head to Low-A or High-A this season. If he were to experience a slight uptick in velocity, Peterson's secondaries and command profile could allow him to project as No. 2 or No. 3 starter, but for now his upside appears capped.