Mazur began his college baseball career at South Dakota State.[3] He went 2–7 with a 5.43 ERA and 88 strikeouts in 12 starts during his sophomore season. After the season, Mazur transferred to Iowa.[4] During the summer of 2021, he played collegiate summer baseball for the Wareham Gatemen of the Cape Cod Baseball League.[5][6] Mazur was named the Hawkeyes Friday night starter going into his first season with the team.[7][8] Mazur was named the Big Ten Conference Pitcher of the Year at the end of the season.[9]
Professional career
San Diego Padres
The San Diego Padres selected Mazur 53rd overall in the 2022 Major League Baseball draft.[10] He signed with the team and received a $1.25 million signing bonus.[11] In 2023, Mazur split his first professional season between the High–A Fort Wayne TinCaps and Double–A San Antonio Missions. He made 24 appearances (18 starts) for the two affiliates, accumulating a 6–4 record and 2.81 ERA with 90 strikeouts across 96 innings pitched.[12]
Mazur began the 2024 season with San Antonio, recording a 1.95 ERA across 6 starts. He was later promoted to the Triple–A El Paso Chihuahuas, compiling a 7.11 ERA with 18 strikeouts across 4 starts.[13] On June 3, 2024, Mazur was selected to the 40-man roster and promoted to the major leagues for the first time.[14] He made his debut the next day. In 8 starts for San Diego, Mazur struggled to a 7.49 ERA with 22 strikeouts across 33+2⁄3 innings pitched.
Mazur was optioned to Triple-A Jacksonville to begin the 2025 season.[16] Mazur made six starts for Miami, compiling an 0-4 record and 4.80 ERA with 19 strikeouts over 30 innings of work.
On March 11, 2026, Mazur underwent Tommy John surgery, ruling him out for the entirety of the season.[17]
