Mason Miller

Mason James Miller (born August 24, 1998), nicknamed "the Reaper", is an American professional baseball pitcher for the San Diego Padres of Major League Baseball (MLB). He has previously played in MLB for the Oakland Athletics / Athletics. He made his MLB debut in 2023, and was an All-Star selection in 2024 and 2026.

Amateur career Miller played for Bethel Park High School in Bethel Park, Pennsylvania, while being homeschooled, and played college baseball at Waynesburg University for four years until he graduated. He then played for Gardner-Webb University for his fifth year as a graduate student. As a sophomore at Waynesburg, he was diagnosed with Type 1 diabetes.

Professional career Oakland Athletics / Athletics Minor leagues The Oakland Athletics selected Miller in the third round of the 2021 Major League Baseball draft. He made his professional debut that year with the Arizona Complex League Athletics. In 2022, Miller pitched in only six games between the ACL Athletics, Lansing Lugnuts and Las Vegas Aviators. After the season, he played in the Arizona Fall League.

Miller began the 2023 season with the Double-A Midland RockHounds, starting one game for the team before being moved up to Triple-A Las Vegas. After one start in Triple-A, on April 18, 2023, with 11 strikeouts over 5 perfect innings, the Athletics announced that Miller would be promoted to the major leagues for the first time.

Major leagues

2023 Miller made his debut a day later, April 19, 2023, in a game against the Chicago Cubs. He pitched 4 innings, allowing two runs on four hits, a walk, and five strikeouts. Miller also became the 10th starting pitcher since the debut of Statcast to throw 15 pitches above . After a May 8 start against the Kansas City Royals, it was reported that Miller was dealing with elbow tightness. He was later diagnosed with a mild sprain of the ulnar collateral ligament in his throwing elbow and promptly shut down from throwing. On June 30, he was transferred to the 60-day injured list. On September 6, Miller was activated from the injured list, with manager Mark Kotsay noting that he would be slated for a relief role. Miller finished the 2023 season with a 3.78 ERA in 10 games, 6 of which were starts.

2024: Rookie season & All-Star In an effort to maintain Miller's health, the A's announced that Miller would be a reliever during the 2024 season. Beginning the season as the team's closer, Miller earned his first career save in a 4–3 win at Texas on April 9. Miller was named MLB Reliever of the Month for April 2024 after earning 8 saves in 8 opportunities and 28 total strikeouts.

On July 7, 2024, Miller was named as a reserve player in the 2024 Major League Baseball All-Star Game, having recorded a 2.39 ERA with 14 saves and 66 strikeouts (leading all AL relievers) up to that point. During the All-Star Game, Miller recorded a scoreless fifth inning with two strikeouts, ultimately earning the win as the American League beat the National League 5–3. During that inning he threw the fastest pitch in All-Star Game history, a 103.6 MPH fastball to Trea Turner.

On September 26, 2024, Miller became the last pitcher to throw a pitch at the Oakland Coliseum in a major league game. He closed out the 3–2 victory over the Texas Rangers with a groundout from Travis Jankowski, recording his 28th save of the year, and the franchises' final win in Oakland. During this outing, Miller set the new franchise record for saves recorded by a rookie with 28, and threw the fastest pitch in Oakland Coliseum history, at 103.8 MPH.

Miller finished the 2024 season with a 2.49 ERA, 28 saves, and 104 strikeouts across 55 games.

2025 On April 12, 2025, Miller recorded the Athletics' first save at Sutter Health Park in Sacramento, after throwing a scoreless 9th inning to close out a 3–1 victory over the New York Mets. Miller recorded a 3.76 ERA with 20 saves and 59 strikeouts across 38 games for the Athletics in 2025. On August 6, Miller recorded his first save as a Padre, striking out all three batters in the 9th inning to close out a 3–2 victory over the Arizona Diamondbacks. On September 3, in the eighth inning versus the Baltimore Orioles, Miller became just the second Padre to pitch an immaculate inning, striking out Jeremiah Jackson, Ryan Mountcastle, and Emmanuel Rivera, on nine consecutive sliders. Miller ended his year with the Padres with a 0.77 ERA, 2 saves in 3 opportunities, and 45 strikeouts in 23.1 innings.

Against the Arizona Diamondbacks on April 25, 2026, Miller broke the Padres team record for consecutive scoreless innings, set 20 years earlier by Cla Meredith with shutout innings in 2006. Miller's streak dated back to August 2025, when he allowed a run in his second appearance with the Padres. His streak ended at against Chicago on April 27 after he allowed two runs in a non-save situation. It was the eighth-longest streak by an MLB relief pitcher since the expansion era began in 1961. On May 19, Miller suffered his first loss as a Padre and his first loss in his career since May 17, 2025 while with the Athletics.

Personal life Miller is a Christian. He is married to Jordan Miller. He is an Eagle Scout. He grew up as a fan of the Pittsburgh Pirates.