Track Record: Lopez's jagged path through the minors culminated with his first trip to the majors in September, and after an ugly debut that went homer, triple, homer, he rebounded during the rest of the month to show the sort of dominant stuff that looks like it could be right at home in a late-inning role.

Scouting Report: Originally signed for a bonus of more than $8 million in January 2015, Lopez left his Double-A team without permission in each of his first two seasons as a pro. He has never spoken publicly about the reasons why, but the departures raised concerns about his makeup. He has gone about reshaping opinions and is no longer viewed as a bad teammate. Lopez has some of the best stuff of any reliever in the organization, featuring a fastball that touched 99 mph and sat 97 in September to go with a swing-and-miss slider that sits in the mid-80s. He also appears to have the mentality for the ninth; during an outing against the Dodgers he escaped a jam and glared at Manny Machado on his way off the field.

The Future: Lopez's pure stuff and reshaped attitude give him a chance to win a roster spot in the spring. He could work his way into a prominent bullpen role.