Mason Miller

Athletics right-hander Mason Miller has broken out as one of the most dominant relievers in the world this year, which will lead to an interesting decision about his future role. He tells Bob Nightengale of USA Today that he’s open to returning to the rotation down the line but also appears somewhat tempted to stick where he’s having success.

“I don’t think I want to close that opportunity,” Miller said of possibly starting someday. “If the opportunity presents itself, maybe, but with the success I’ve had [as a closer], I think it’s a difficult decision to say I want to get away from that.”

Miller, 25, was primarily a starter in college but wasn’t able to stay healthy in his first few professional seasons. He was drafted in 2021 but then was held back by a shoulder strain in 2022, limited to just 14 innings over six minor league starts. Last year, he made two minor league starts and four in the majors before landing on the injured list with forearm tightness. He was eventually diagnosed with a sprained UCL in his throwing elbow and avoided surgery but wasn’t able to return until September.

In December, general manager David Forst discussed Miller’s situation, with Martín Gallegos of MLB.com relaying his sentiments on X. Forst said the club was planning to have Miller serve in a relief role in 2024, with a return to starting a possibility down the road, but they wanted him to stay healthy for a full season first.

As mentioned, 2024 has been a banner year for Miller so far in that relief role. He already has 15 saves and a 2.27 earned run average in 39 2/3 innings. He has struck out an incredible 46.7% of batters faced. Among pitchers with at least 20 innings pitched this year, Josh Hader is second in the strikeout rate category but well behind Miller at 40.4%. He has been selected to his first All-Star team this year.

If Miller stays healthy in the second half, the question will turn to what comes next and it appears the A’s don’t yet have a firm decision. “I don’t know,” A’s manager Mark Kotsay said to Nightengale. The skipper added that he didn’t want to rule anything it out but they are still focused on keeping Miller healthy in 2024, before addressing the inherent pros and cons of the decision. “There’s more value there in the innings, but obviously there’s more impact with the opportunity for us to win a game at the back end with him being the closer.’’

This season, various players have attempted to the reliever-to-starter move, with varying degrees of success. MLBTR’s Steve Adams recently took a look at the results, with Garrett Crochet and Reynaldo López two of the best success stories with A.J. Puk on the other end of the spectrum.

The A’s control Miller for another five seasons after this one and are currently rebuilding. That gives them some leeway to experiment if they and Miller decide that they want to, but there would also be an argument for simply continuing with what’s working. Many closers around baseball are former starters who were put into late-inning roles due to health issues or workload concerns, then were simply kept there because it was working.

Miller is one of the hardest throwers in baseball, averaging 100.9 miles per hour. He already has the UCL sprain and the significant shoulder strain on his track record. He would likely have to pull back on the velocity a bit if he were to move into a starter’s role but it would still be a new challenge keeping his body healthy for the marathon of starting for a full season, as opposed to the high-octane relief role he’s been in this year.

Broadly speaking, having an effective starting pitcher give a club 150 to 200 quality innings is more valuable than 50 to 60 innings of relief work. That’s why the best starting pitchers are paid more than the best relievers, both in arbitration and in free agency. Controllable starters also tend to bring back larger returns when traded, as compared to their relief counterparts. Miller has been speculated as a trade candidate this season, reportedly drawing lots of interest, though with the A’s setting a high asking price. They would likely have to be blown away to trade five-plus years of such a dominant pitcher and the possibility of him returning to a rotation down the line could conceivably give him even more trade value at some point.

Both the A’s and Miller would stand to benefit if he could successfully take on a rotation role, but whether they pursue it or not could depend on the comfort level from both sides, as well as the ongoing monitoring of his health.

The A’s are receiving early trade calls on closer Mason Miller, writes Ken Rosenthal of the Athletic. While the team is at least broadly open to discussions, Rosenthal reports that no one has come close to what is understandably a huge ask.

Miller has been one of the league’s breakout players in 2024. It certainly didn’t come out of nowhere — he has been widely regarded as a Top 100 prospect in each of the last two years — but the second-year righty is already one of the best relievers in the game. Miller gave up two runs in his first appearance of the season against the Guardians. He hasn’t been scored on in 12 games since, and that understates his dominance.

The 25-year-old has recorded multiple strikeouts in all but two of his outings. He has fanned 33 of the 60 batters who have stepped in against him. That’s a laughable 55% rate. Among pitchers with at least 10 innings, Cincinnati’s Fernando Cruz ranks second with a 47.3% strikeout percentage. Only four qualified relievers — Devin Williams (during the abbreviated 2020 schedule), Aroldis Chapman (2014), Craig Kimbrel (2012) and Edwin Díaz (2022) — have ever maintained a strikeout rate north of 50% over a full season. Miller has induced swinging strikes on more than 21% of his pitches, a mark only narrowly topped by Cruz. He has paired that overwhelming stuff with strong control, issuing just four walks without hitting a batter.

[Related: The A’s Overpowering Closer]

It’s not difficult to understand why opponents haven’t had any success making contact. Miller’s stuff is off the charts. His fastball is averaging 100.8 MPH and can run into the 103-104 MPH range at its high end. He has paired it with an upper-80s slider that drew plus or better reviews from prospect evaluators and has been nearly unhittable. Opponents are coming up empty almost half the time they swing at both offerings.

Every bullpen would be massively upgraded with Miller at the back end. It’s entirely unsurprising that teams would look to pry him from Oakland and that the A’s would need a massive haul to consider it. On top of Miller’s dominance, he’s under affordable club control for years to come. He entered 2024 with less than one season of MLB service. He’s not on track to reach free agency until the end of the 2029 campaign. Miller is a lock to go through arbitration four times as a Super Two player, but that won’t begin until after next season.

The A’s are still deep into a rebuild despite a reasonable 18-21 start. They’re very unlikely to hang in the playoff mix this year, although they surely anticipate being a legitimate contender well within Miller’s window of team control. A player of this caliber who still has five-plus years of control being traded is essentially unheard of.

However, Miller’s status is at least somewhat clouded by an alarming injury history. He barely pitched in the minors in 2022 because of shoulder troubles. The A’s nevertheless called him up early last season to work from the rotation. Miller made four starts before being diagnosed with a UCL sprain in his elbow. He was shelved into September. The A’s used him out of the bullpen for 2-3 inning stints once he returned.

GM David Forst announced early last offseason the A’s would move Miller to late-inning relief this year in an effort to keep him healthy. They’ve maintained they’re not opposed to stretching him back out as a starter in ’25, although he may wind up being so impressive as a reliever the team chooses not to mess with success.

There’s no small amount of stress put on the arm of a pitcher who throws as hard as Miller does. The front office presumably has some concern about the possibility he suffers another significant injury. That would be the main argument for genuinely considering trade offers, though Miller also clearly has the talent to be a franchise building block. That’s particularly true if the A’s are serious about potentially moving him back to the rotation in 2025.

Significant trades this early in the season are rare, although the Padres and Marlins lined up on the Luis Arraez swap last week. Teams will certainly continue trying to tempt the A’s as the deadline gets closer. Miller would be their most valuable trade chip, while players like Paul Blackburn, Brent Rooker, Ross Stripling and Alex Wood could draw attention.

Speculatively speaking, Lucas Erceg could also emerge as one of the more intriguing relievers on the deadline market. A former third baseman, Erceg was a late convert to pitching whom the A’s acquired from the Brewers in a minor trade nearly a year ago. While he struggled to a 4.75 ERA over 55 innings as a rookie, he has been a key high-leverage arm for skipper Mark Kotsay in 2024. Erceg has managed 22 strikeouts over 15 frames of 3.60 ERA ball. His fastball is sitting in the 98-99 MPH range.

Erceg also has six years of team control, so there’s no urgency for the A’s to move him. He’s already 29 years old and not as overpowering as Miller, though, so he’s less likely to be a major long-term piece coming out of the rebuild.