Bio
Mason Pennington arrives in Sioux City after ascending to the top of the Southeast Missouri State rotation in 2026. This season, he made 15 starts, taking over the coveted Friday night role and delivering one of the strongest campaigns of his career. He threw 77.1 innings, struck out 71, walked just 21, and finished with a 3.61 ERA, a 7–3 record, and a .242 opponent average.
His 2026 breakout followed a developmental year in 2025, when he made 11 appearances (five starts) and logged 35.1 innings. That season included a season‑high 6.0‑inning outing at Southern Illinois, a five‑strikeout performance against Murray State, and a hitless appearance versus Eastern Illinois. He finished the year with a 5.60 ERA and a 1–1 record.
Before arriving at SEMO, Pennington began his collegiate career at Northeastern Oklahoma A&M, where he first took the mound and quickly emerged as a reliable arm.
Over two seasons, he made 28 appearances, threw 123.1 innings, and struck out 102 hitters. He posted a 5.73 ERA in his first season and a 4.24 ERA in his second, earning Honorable Mention All‑Region honors.
A native of Owasso, Oklahoma, Pennington played at Owasso High School, where he earned Honorable Mention All‑State recognition and helped lead the Rams to a Regional Championship, all before he ever stepped on a mound as a pitcher.