Luis Frias

Even scouts who think Frias is destined to be a reliever can't help but marvel at how special his arm is. A physical 6-foot-3 righty, Frias' mid-90s fastball and hammer curveball are at least plus pitches, with both flashing as 70-grade offerings last year. Originally signed in 2015 as an infielder, Frias didn't emerge as a notable prospect until 2018 in the AZL, so the fact he is 21 and has not pitched above Low-A is not a concern, although he will need to be added to the 40-man roster next offseason. His mechanics are inconsistent, which leads to questions about his future command. He has added a changeup and slider to the mix, but those pitches need further refinement. Frias pitches with swagger and confidence -- traits that should serve him well as he climbs the ladder. His ability to throw strikes on a consistent basis will determine whether he is a high-leverage reliever or impact starter.