Brennan Seiber, a 6‑foot‑6 right‑handed reliever, has announced his commitment to Oregon State for his senior season, bringing a blend of size, experience and a polished pitch arsenal to the Beavers’ mound.
Commitment and background
A native of Newport Beach, California, Seiber first rose to prominence at Mater Dei High School, where he was ranked among the nation’s top 500 prospects and the 369th right‑handed pitcher in the 2023 recruiting class.
During his three‑year tenure at Vanderbilt, he appeared in 58 games, amassing a 9‑3 record and a 4.40 ERA over 108 ⅓ innings, while showcasing a sinker that sits in the low‑90s and a slider that hovers in the high‑70s to low‑80s.
Summer performance and pitch mix
This summer, Seiber has worked primarily out of a low slot, mixing a mid‑80s cutter with his sinker and slider, and has shown flashes of the dominance that made him a two‑time Cape Cod League alum with the Orleans Firebirds.
A new era for the pitching staff
The move also marks the first pitching staff assembled under new coach Andrew Moore, who will look to build on the legacy of former Beavs reliever Isaac Yeager and shape Seiber into a bullpen anchor for the 2027 roster.