Mason Miller Bio
Mason James Miller, born on August 24, 1998, is an American professional baseball pitcher for the San Diego Padres of Major League Baseball (MLB). He previously played in MLB for the Oakland Athletics, making his big-league debut in 2023 and earning an All-Star selection in 2024. A hard-throwing right-handed reliever, Miller has quickly built a reputation as one of the most dominant young closers in the game.
Known for his triple-digit fastball and high strikeout totals, Miller has drawn national attention since his first full MLB season. After being traded to San Diego in mid-2025, he continued to produce at an elite level and helped anchor the Padres’ bullpen during the postseason.
Early Life and Background
Mason James Miller was born and raised in Bethel Park, Pennsylvania. He grew up in a supportive household in the South Hills region near Pittsburgh and attended Bethel Park High School, where he played for the school’s baseball team. As a teenager, Miller was homeschooled for part of his education, which allowed him the flexibility to develop as a young athlete while staying close to his community.
As a child, Miller followed the Pittsburgh Pirates, the local MLB franchise, which helped shape his love for the sport. He also achieved the rank of Eagle Scout through the Boy Scouts of America, reflecting a disciplined and focused upbringing outside of athletics.
During his sophomore year at Waynesburg University, Miller was diagnosed with Type 1 diabetes, a serious health challenge that required daily management. Despite this setback, he continued to pitch at a high level and used the diagnosis as motivation to refine his preparation and conditioning routines.
Path to Professional Baseball
After graduating from Waynesburg University, where he played college baseball for four years, Miller used his remaining NCAA eligibility to play a fifth year at Gardner-Webb University as a graduate student. His college progression showed steady improvement in velocity and command, helping him attract attention from professional scouts.
In the 2021 Major League Baseball Draft, the Oakland Athletics selected Mason Miller in the third round, recognizing his powerful arm and projectable frame. He signed with the organization and reported to the Arizona Complex League Athletics to begin his professional career later that year.
In 2022, Miller pitched in only six minor-league games across the ACL Athletics, Lansing Lugnuts, and Las Vegas Aviators while recovering and building strength. After the regular season, he gained valuable experience by pitching in the Arizona Fall League, a respected developmental circuit for top prospects.
Mason Miller Career
Minor-League Career (2021–2023)
Mason Miller began the 2023 season with the Double-A Midland RockHounds, where he started one game before a quick promotion to Triple-A Las Vegas. In his lone Triple-A start, he delivered 11 strikeouts across five perfect innings, a dominant performance that immediately caught the Athletics’ attention.
On April 18, 2023, Oakland announced that Miller would be promoted to the major leagues for the first time. The fast rise through the minors confirmed his status as one of the organization’s top pitching prospects and set the stage for his big-league debut the following day.
Oakland Athletics Era (2023–2025)
Mason Miller made his MLB debut on April 19, 2023, against the Chicago Cubs, pitching four and a third innings and allowing two runs on four hits with five strikeouts. He quickly made headlines by becoming the tenth starting pitcher since the introduction of Statcast to throw at least 15 pitches above 100 mph, showcasing the elite velocity that defined his early career.
Elbow tightness surfaced after a May 2023 start against the Kansas City Royals, and Miller was later diagnosed with a mild ulnar collateral ligament sprain. He was shut down from throwing and transferred to the 60-day injured list in late June. After his September activation, manager Mark Kotsay moved him into a relief role to protect his arm long-term.
In 2024, the Athletics committed to Miller as their closer, and he delivered immediately. He earned his first career save on April 9, 2024, in a 4–3 win at Texas and was named MLB Reliever of the Month for April after converting eight saves with 28 strikeouts. On July 7, 2024, he was selected as a reserve for the 2024 MLB All-Star Game, where he recorded a scoreless fifth inning with two strikeouts and was credited with the win after throwing a 103.6 mph fastball to Trea Turner, the fastest pitch in All-Star Game history.
Miller closed the 2024 regular season with a 2.49 ERA, 28 saves, and 104 strikeouts across 55 games, earning All-MLB Second Team honors and finishing fourth in American League Rookie of the Year voting. On September 26, 2024, he became the final pitcher to throw at the Oakland Coliseum in a major-league game, recording his 28th save in a 3–2 win over the Texas Rangers and setting the franchise’s rookie saves record while also delivering the fastest pitch ever recorded at the Coliseum, at 103.8 mph.
San Diego Padres Era (2025–Present)
On July 31, 2025, the Oakland Athletics traded Mason Miller and JP Sears to the San Diego Padres in exchange for prospects Leo De Vries, Braden Nett, Eduarniel Núñez, and Henry Baez. The move paired Miller with a contender and gave the Padres a power arm for the late innings.
On August 6, 2025, Miller recorded his first save as a Padre, striking out all three batters in the ninth inning to seal a 3–2 victory over the Arizona Diamondbacks. He later made franchise history on September 3, 2025, becoming just the second Padre to pitch an immaculate inning when he struck out Jeremiah Jackson, Ryan Mountcastle, and Emmanuel Rivera on nine consecutive sliders against the Baltimore Orioles.
Mason Miller finished the 2025 regular season with a combined 2.63 ERA, 22 saves, and 104 strikeouts across 60 games between the Athletics and Padres. In Game 1 of the 2025 National League Wild Card Series against the Chicago Cubs, he made his postseason debut and struck out all three batters he faced in the seventh inning, although Chicago won the game 3–1.
Driving Style and Strengths
Mason Miller relies on an overpowering fastball that routinely sits in the upper 90s and has touched more than 103 mph, paired with a sharp breaking slider. He generates swings and misses at an elite rate, which allows him to thrive in high-leverage relief spots and shorten games for his team.
Notable Events and Milestones
Among his signature moments, Miller threw the fastest pitch in All-Star Game history at 103.6 mph in 2024 and recorded an immaculate inning for the Padres in September 2025. He also set the Athletics’ rookie saves record with 28 saves that same year and closed out the final major-league game at the Oakland Coliseum.
Mason Miller Career Wins
Mason Miller has built a strong résumé across his MLB career, combining closing duties with elite strikeout numbers. Through the 2025 season, he had already recorded 50 regular-season saves and surpassed 200 strikeouts in only 125 major-league appearances.
MLB Highlights
Mason Miller recorded his first MLB save on April 9, 2024, in a 4–3 win at Texas and closed the 2024 regular season with 28 saves for the Athletics. He added his first save as a Padre on August 6, 2025, against the Arizona Diamondbacks and finished 2025 with 22 total saves across both clubs.
Beyond saves, Miller collected 11 strikeouts across five perfect innings in his lone Triple-A start in 2023 and struck out all three batters he faced in Game 1 of the 2025 NL Wild Card Series. He also earned the win in the 2024 MLB All-Star Game after a scoreless fifth inning.
Other Performances
Mason Miller gained valuable experience in the Arizona Fall League after the 2022 season, a traditional development step for top pitching prospects. He also posted a 0.77 ERA across 22 games with the Padres in 2025, a small-sample stretch that highlighted his dominance after the midseason trade.
Mason Miller Family
Family Background and Baseball Lineage
Mason Miller was raised in Bethel Park, Pennsylvania, by a supportive family that nurtured his early interest in baseball. He grew up cheering for the Pittsburgh Pirates and developed his athletic foundation in that community before moving on to college baseball at Waynesburg University and Gardner-Webb University.
Personal Life
Miller is an Eagle Scout, reflecting years of commitment to the Boy Scouts of America. Diagnosed with Type 1 diabetes during his sophomore year at Waynesburg, he has managed the condition throughout his professional career while maintaining one of the most demanding workloads in MLB bullpens.
2025 Season Performance
Mason Miller began 2025 as the Oakland Athletics’ closer, recording the franchise’s first save at Sutter Health Park in Sacramento on April 12 against the New York Mets. He posted a 3.76 ERA with 20 saves and 59 strikeouts across 38 games before the trade, anchoring the bullpen during the team’s transition to a new home ballpark.
After arriving in San Diego on July 31, 2025, Miller quickly became a late-inning weapon for the Padres. He recorded an immaculate inning on September 3, closed the regular season with a 0.77 ERA in 22 games, and struck out the side in his postseason debut during the Wild Card Series against the Cubs.
Looking ahead, Miller is expected to remain a central part of the Padres’ bullpen plans, with his power arm and high strikeout rate providing a foundation for future postseason pushes. His combination of velocity, poise, and durability positions him as a long-term closer candidate in San Diego.