Michael Kenechukwu Petersen Bio
Michael Kenechukwu Petersen (born May 16, 1994) is an American professional baseball pitcher for the Miami Marlins of Major League Baseball (MLB). He has previously played in MLB for the Los Angeles Dodgers and Atlanta Braves, and he made his MLB debut in 2024. A former 17th-round draft pick, Petersen has built his career through perseverance, multiple organizations, and a journey that has crossed the United States, England, and international competition.
Now wearing No. 49 for the Marlins, Petersen works as a relief pitcher and has continued to evolve as a strike-throwing arm out of the bullpen. His professional path has included stops in the minor leagues, a Tommy John surgery recovery, and a brief appearance on the international stage representing Great Britain at the 2023 World Baseball Classic.
Early Life and Background
Michael Kenechukwu Petersen was born in London, England, on May 16, 1994. He was born to an American father and a Nigerian mother, giving him a multicultural upbringing that shaped his early years abroad. When Petersen was one year old, his family relocated to California, his father’s home state, where he would spend most of his childhood and develop his love for the game of baseball.
Petersen grew up in San Jose, California, and attended Saint Francis High School, where he played baseball and drew early attention from professional scouts. His multicultural background, including ties to both the United States and the United Kingdom, has been a defining part of his personal identity and later influenced his decision to represent Great Britain in international competition.
Path to Professional Baseball
Petersen’s path to professional baseball was marked by persistence and multiple draft opportunities. He was first selected by the Pittsburgh Pirates in the 19th round of the 2012 MLB draft out of Saint Francis High School but chose not to sign, opting instead to continue his development. The following year, he was drafted by the Texas Rangers in the 31st round of the 2013 MLB draft out of West Valley College and again decided not to sign.
After one year at West Valley College, Petersen transferred to Riverside City College, where he played a single game in the 2014 season, recording 1⅓ innings pitched, two strikeouts, and no runs allowed. That same year, he was drafted by the San Francisco Giants in the 24th round of the 2014 MLB draft, but he did not sign. Finally, in 2015, the Milwaukee Brewers selected him in the 17th round, and Petersen agreed to begin his professional career with a $100,000 signing bonus.
Michael Kenechukwu Petersen Career
Milwaukee Brewers (2015–2019)
Petersen began his professional career in 2015 with the Arizona League Brewers before advancing to the Helena Brewers in 2016 and 2017. In 2018, pitching for the Wisconsin Timber Rattlers, he appeared in 32 games and posted a 3.72 earned run average, and in 2019 with the Carolina Mudcats, he produced a 3.17 ERA across 41 appearances. These steady minor league results helped him develop into a reliable relief prospect within the Brewers organization.
Colorado Rockies (2019–2023)
On December 12, 2019, Petersen was claimed off waivers by the Colorado Rockies. He did not play in 2020 after the minor league season was canceled because of the COVID-19 pandemic. Petersen then missed the entire 2021 season after undergoing Tommy John surgery on May 5, 2021. While rehabbing, he made only one appearance in 2022 in the Arizona Complex League, and in 2023, he split the season between the Double-A Hartford Yard Goats and the Triple-A Albuquerque Isotopes, combining for 41 games and a 4.10 ERA.
Los Angeles Dodgers (2024)
Petersen signed a minor league contract with the Los Angeles Dodgers on January 24, 2024, and began the year with the Triple-A Oklahoma City Baseball Club. On June 16, 2024, he was selected to the 40-man roster and promoted to the major leagues for the first time. He made his MLB debut two days later against the Colorado Rockies, allowing one run on one hit and one walk while striking out two in two innings to pick up the win, with his first strikeout victim being Elehuris Montero.
In 11 games for the Dodgers, Petersen pitched 14 innings, recording three wins, a 6.43 ERA, and 11 strikeouts. He also appeared in 35 games for Oklahoma City, posting a 1.64 ERA with 10 saves and 44 strikeouts. The Dodgers designated him for assignment on September 8, 2024.
Los Angeles Angels and Atlanta Braves (2025)
On November 4, 2024, Petersen was claimed off waivers by the Toronto Blue Jays. He was designated for assignment following the signing of Max Scherzer on February 4, 2025, and on February 11, 2025, he was claimed off waivers by the Los Angeles Angels. He was optioned to the Triple-A Salt Lake Bees to begin the season, and after one appearance for Salt Lake, he was designated for assignment on March 31, 2025.
On April 1, 2025, Petersen was traded to the Atlanta Braves in exchange for cash considerations. In four appearances for the Braves, he accumulated a 4.05 ERA with five strikeouts across 6⅔ innings pitched. Atlanta designated him for assignment on July 13, 2025.
Miami Marlins (2024 and 2025–Present)
On September 10, 2024, Petersen was claimed off waivers by the Miami Marlins. In five appearances for the Marlins that September, he logged a 4.76 ERA with three strikeouts across 5⅔ innings pitched. After a circuitous offseason, on July 16, 2025, he was traded to the Miami Marlins in exchange for cash considerations, beginning his second stint with the organization.
International Career
Petersen pitched for Great Britain at the 2023 World Baseball Classic, working one scoreless inning and striking out Nolan Arenado. His participation reflected his British birth and his family’s international roots.
Michael Kenechukwu Petersen Personal Life
Family Background
Michael Kenechukwu Petersen was born in London, England, to an American father and a Nigerian mother, and the family moved to California when he was one year old. He grew up in San Jose and attended Saint Francis High School before continuing his baseball journey through the junior college ranks. His multicultural heritage and American upbringing have helped define both his personal identity and his international baseball opportunities.
Michael Kenechukwu Petersen 2025 Season Performance
Petersen’s 2025 season has been defined by movement between organizations. After beginning the year in the Los Angeles Angels system, he was traded to the Atlanta Braves on April 1, 2025, and posted a 4.05 ERA in four major league appearances. The Braves designated him for assignment on July 13, 2025, and three days later, on July 16, 2025, he was traded back to the Miami Marlins in exchange for cash considerations.
Through June 21, 2026, Petersen has appeared in relief for Miami, and his major league statistics include a 4–2 win-loss record, a 4.24 earned run average, and 69 strikeouts. His return to the Marlins organization has provided a familiar landing spot as he continues to develop into a dependable bullpen arm.
Looking ahead, Petersen remains focused on establishing consistency out of the Marlins bullpen and building on the strikeout totals he has produced in 2025. With a recovered elbow and a clearer organizational home, he has positioned himself to compete for a more defined role in Miami’s relief corps going forward.
