Isaac Mattson Bio
Isaac Gerald Mattson, born on July 14, 1995, is an American professional baseball pitcher who currently competes in Major League Baseball (MLB) for the Pittsburgh Pirates. He has previously played in MLB for the Baltimore Orioles, the organization that first promoted him to the major leagues in 2021. Since being selected by the Los Angeles Angels in the 2017 MLB Draft, Mattson has built a long professional journey through the minor leagues, independent baseball, and the major league roster, establishing himself as a reliable relief pitcher.
Early Life and Background
Isaac Gerald Mattson was born in Harborcreek, Pennsylvania, a small community in the northwestern part of the state near Lake Erie. He is the son of Edward and Debra Mattson and was raised alongside seven siblings in a large and active household. His mother, Debra, passed away in July 2021, a personal loss that has shaped the pitcher and his family in the years since.
Mattson attended Harbor Creek High School, where he was a multi-sport athlete in both baseball and basketball. During his senior year in 2014, he posted an exceptional pitching line of 6-0 with a 0.67 earned run average (ERA) while also batting .531 at the plate. Despite those numbers, he went undrafted in the 2014 MLB Draft and chose to continue his baseball career at the collegiate level.
Path to Professional Baseball
Following high school, Mattson enrolled at the University of Pittsburgh, where he played college baseball for the Panthers. As a freshman in 2015, he appeared in 22 games and posted a 1-1 record with a 3.82 ERA. He continued to develop in 2016, pitching 34 innings in relief and going 2-0 with a 3.71 ERA during his sophomore season.
After his sophomore year, Mattson played for the Chatham Anglers of the Cape Cod Baseball League, the premier summer collegiate league in the United States, and earned all-star recognition. He returned to Pitt for his junior year in 2017 and went 1-0 with a 2.87 ERA and 41 strikeouts in 31 innings out of the bullpen, finishing his college career on a strong note and setting the stage for the MLB Draft.
Isaac Mattson Career
Early Career (2017-2019)
After his junior season at Pitt, Mattson was selected by the Los Angeles Angels in the 19th round of the 2017 MLB Draft. He made his professional debut that summer with the Arizona League Angels before being promoted to the Orem Owlz, where he was named an All-Star. Across 31 and one-third innings, he posted a 1-0 record and a stellar 1.44 ERA.
In 2018, Mattson split his season between the Burlington Bees and the Inland Empire 66ers, going 7-4 with a 3.82 ERA in 25 games, including 11 starts. He returned to the 66ers in 2019 and was promoted to the Mobile BayBears in May and then to the Salt Lake Bees in August. Across 37 relief appearances that year, he went 6-3 with a 2.33 ERA and 110 strikeouts in 73 and one-third innings, earning a selection to the Arizona Fall League with the Mesa Solar Sox.
Baltimore Orioles (2019-2022)
On December 4, 2019, Mattson was traded to the Baltimore Orioles as part of a package headlined by Dylan Bundy going the other way. He did not appear in a minor league game in 2020 after the season was canceled because of the COVID-19 pandemic. On November 20, 2020, the Orioles added him to their 40-man roster, and on May 3, 2021, he was promoted to the major leagues for the first time.
Mattson made his MLB debut on May 7, 2021, pitching two-thirds of an inning and allowing one run. He recorded his first career strikeout on July 3, 2021, fanning Los Angeles Angels infielder David Fletcher. He was optioned and recalled several times during the season before being outrighted in April 2022 and ultimately released by Baltimore in July 2022.
Independent Ball and Return to Affiliated Baseball (2022-2023)
After his release from the Orioles organization, Mattson signed with the Washington Wild Things of the Frontier League on August 6, 2022. In 12 appearances for Washington, he posted a 2.40 ERA with 23 strikeouts across 15 innings. In March 2023, he joined the Southern Maryland Blue Crabs of the Atlantic League of Professional Baseball, where he logged a 3.32 ERA with 24 strikeouts and 3 saves in 18 outings.
On June 22, 2023, Mattson signed a minor league contract with the Minnesota Twins. Pitching for the Double-A Wichita Wind Surge, he registered a 3.62 ERA and 42 strikeouts across 32 and one-third innings in 21 appearances. He elected free agency on November 6, 2023.
Pittsburgh Pirates Era (2023-Present)
On December 11, 2023, Mattson signed a minor league deal with the Pittsburgh Pirates. He began 2024 with the Double-A Altoona Curve, was promoted to the Triple-A Indianapolis Indians, and combined for a 7-2 record and 3.17 ERA with 89 strikeouts over 37 games. The Pirates selected his contract on September 19, 2024, and he posted a 5.06 ERA with 6 strikeouts in 5 and one-third innings across three major league appearances before being removed from the 40-man roster after the season.
He re-signed with Pittsburgh on a minor league deal in November 2024 and returned to Indianapolis to start 2025, posting a 2.50 ERA with 22 strikeouts and 4 saves in his first 16 outings. The Pirates selected his contract again on May 20, 2025, and on June 7, 2025, he earned his first career major league win by tossing a scoreless seventh inning against the Philadelphia Phillies. Mattson went on to appear in 44 relief outings for Pittsburgh, finishing 3-3 with a 2.45 ERA and 45 strikeouts across 47 and two-thirds innings.
Driving Style and Strengths
Mattson has built his career as a late-inning relief pitcher who relies on a strong strikeout rate and the ability to handle high-leverage situations. His development through independent baseball sharpened his command, and his minor league track record consistently featured low-to-mid ERA marks and double-digit strikeout totals relative to innings.
Notable Events and Milestones
Some of the defining moments of Mattson’s career include his 2017 debut with the Arizona League Angels and Orem Owlz, his major league debut with the Orioles on May 7, 2021, his first career strikeout of David Fletcher on July 3, 2021, and his first MLB win on June 7, 2025, against the Phillies. Each of those steps marked a meaningful advance in a long and winding professional path.
Isaac Mattson Career Wins
Isaac Gerald Mattson has accumulated his wins across the minor leagues, independent baseball, and MLB. His first MLB victory came on June 7, 2025, while pitching for the Pittsburgh Pirates. He has also recorded double-digit win totals at multiple minor league stops, including the 2024 season in which he went 7-2 between Double-A and Triple-A.
Major League Highlights
In his MLB career through 2025, Mattson made 47 relief appearances, including 44 for Pittsburgh, and finished 3-3 with a 2.45 ERA and 45 strikeouts in 47 and two-thirds innings during the 2025 season. His first major league win, a scoreless inning against Philadelphia, signaled his emergence as a trusted option out of the Pittsburgh bullpen.
Minor League and Independent Highlights
Mattson’s minor league journey includes a 7-4 record in 2018, a 6-3 mark in 2019, and a combined 7-2 record across Double-A and Triple-A in 2024. In independent baseball, he was effective in short stints with both the Washington Wild Things and the Southern Maryland Blue Crabs, and he was selected for prestigious events like the Arizona Fall League and the Cape Cod League all-star game.
Isaac Mattson Family
Family Background and Personal Life
Isaac Gerald Mattson was born to Edward and Debra Mattson and grew up in Harborcreek, Pennsylvania, as one of eight children. His mother, Debra, passed away in July 2021, an event that has been publicly acknowledged by Mattson and remains a significant part of his family story.
Mattson married his wife, Devin, in November 2022, and the couple welcomed their first child, a son, in February 2025. He has spoken about how fatherhood and family have grounded him through the long journey across multiple organizations and levels of professional baseball.
2025 Season Performance
Isaac Gerald Mattson’s 2025 season marked his most significant major league stretch to date. He opened the year in Triple-A Indianapolis, where he posted a 2.50 ERA with 22 strikeouts and 4 saves in his first 16 outings, earning a return to the big league roster on May 20. From there, he settled into a consistent relief role for the Pirates.
Over 44 relief appearances for Pittsburgh in 2025, Mattson went 3-3 with a 2.45 ERA and 45 strikeouts across 47 and two-thirds innings. His first career major league win on June 7 against the Philadelphia Phillies was a highlight, and his combination of strikeouts and low walk rate made him a dependable late-inning option in the Pirates bullpen.
Entering the next phase of his career, Mattson is positioned as a battle-tested reliever whose independent baseball experience and years of minor league perseverance have translated into stable major league production. With a full big league season now under his belt, he is expected to remain a key piece of the Pirates relief corps moving forward.
