The A’s Overpowering Closer

In what’ll be another rough season for the A’s, the front office is looking for young players to establish themselves as key long-term pieces. In the first few weeks, no one has shown more promise in that regard than Mason Miller.

Miller was a third-round pick in 2021. His stuff had taken a major step forward during his final collegiate season. As The Athletic’s Stephen Nesbitt wrote last week, Miller had a hard time keeping on weight and maintaining his strength until he was diagnosed with Type 1 diabetes in 2018. While the primary concern was in allowing Miller to navigate a serious health condition, learning how to manage the issue permitted the 6’5″ righty to rapidly bulk up. His velocity spiked into the mid-upper 90s, leading the A’s to roll the dice on his upside.

Injuries essentially robbed Miller of traditional minor league development. He lost almost all of the 2022 season to shoulder issues. He had pitched all of 28 2/3 professional innings before the A’s called him up last April. He had an impressive four-start debut before reporting forearm soreness. Testing revealed a mild UCL sprain and the A’s shut him down for a few months. Miller returned in September, working 2-3 inning stints to finish the year. He closed his rookie campaign with a 3.78 ERA in 33 1/3 innings.

Oakland GM David Forst announced early in the offseason that Miller would work out of the bullpen in 2024. Forst suggested it wasn’t a permanent switch. Rather, the A’s were using the 25-year-old in shorter stints in an effort to keep him healthy before a move back to the rotation in 2025. While they certainly had high hopes that his power arsenal would translate, Miller has surpassed even the loftiest expectations in the first few weeks.

Including tonight’s four-out save in the Bronx, Miller is up to 11 1/3 innings of two-run ball. He has successfully locked down all six of his save chances. After allowing two runs in his season debut against the Guardians, he has rattled off eight straight scoreless outings. Four of those have been perfect innings in which he has recorded multiple strikeouts.

Miller has punched out 23 of 45 opposing hitters, the highest strikeout rate in the majors. His already eye-popping stuff has leveled up in short bursts. Miller’s fastball is sitting in the 100-101 MPH range. Both the heater and his upper-80s slider have been essentially untouchable.

Even in a minuscule sample, it doesn’t seem outlandish to call Miller one of the top relievers in MLB. The quality of the arsenal is self-evident. He’s missing bats at the levels we’ve seen from the likes of Edwin Díaz, Félix Bautista and Andrés Muñoz. Given his injury history, one can question whether he’ll be able to stay healthy all season. There’s no reason to doubt his talent.

Miller fell just shy of the cutoff for a full service year in 2023. The A’s control him for six seasons. He’ll qualify for early arbitration as a Super Two player during the 2025-26 offseason. That’ll allow him to go through the arb process four times instead of the standard three, yet Miller could stick with the A’s through the ’29 campaign.

Opposing teams will probably try to convince Forst to put Miller on the trade block this summer, but it’s hard to see any realistic way that he gets moved. Even rebuilding clubs rarely trade relievers with the kind of talent that he possesses when they’re in their pre-arbitration seasons. That’s before considering that the A’s presumably still intend to give him a chance to compete for a rotation spot next year. If Miller turns in a full season as a top 3-5 reliever in the sport, perhaps they’d consider him too valuable to take out of the bullpen, but there’s nothing to suggest their long-term plans have changed at this point.

Image courtesy of USA Today Sports.