Cleveland Indians / Guardians Minor leagues The
Cleveland Indians drafted Brennan in the eighth round, with the 250th overall selection, of the
2019 Major League Baseball draft. After signing with the team he was initially assigned to the rookie-level
Arizona League Indians before being promoted to the
Low-A Mahoning Valley Scrappers. Brennan did not play in a game in 2020 due to the cancellation of the minor league season because of the
COVID-19 pandemic. Brennan was assigned to the
High-A Lake County Captains at the beginning of the 2021 season. He was promoted to the
Double-A Akron RubberDucks after batting .290 in 62 games with Lake County. Brennan began the 2022 season with Akron and was promoted to the
Triple-A Columbus Clippers after hitting .304 with 39 RBI, which was leading the
Eastern League.
Major leagues The Guardians selected Brennan's contract on September 21, 2022, adding him to their active roster. He made his major league debut the same day against the
Chicago White Sox. Brennan hit his first major home run and triple in the same game off of
Max Castillo on October 2. For the season, Brennan hit .357 with eight
RBI and one
home run in 42 at-bats. In five postseason games, he batted 2-for-11 with one RBI and six strikeouts. On May 22, 2023, Brennan accidentally hit and killed a bird with a batted ball during a game against the
Chicago White Sox. The following day, he hit a home run which he dedicated to the memory of the bird. On June 9, he recorded his first walkoff hit in the 14th inning of a 10-9 win against the
Houston Astros. Brennan showed versatility for the Guardians, playing all three outfield positions. He finished the 2023 season with a .266/.299/.356
slash line, five home runs, 41 RBI, and 13 stolen bases across 138 total games. Brennan made 114 appearances for the Guardians during the 2024 campaign, hitting .264/.309/.388 with eight home runs, 30 RBI, and four stolen bases. On May 12, 2025, he was recalled by the Guardians, and went 1-for-11 (.091) with one walk over six appearances for the team. Brennan underwent a season-ending
reconstruction of his left UCL on June 9. On September 6, it was announced that Brennan had undergone an additional surgery, this time to correct a lingering
groin injury. On November 21, he was non-tendered by the Guardians and became a free agent.
San Francisco Giants On February 15, 2026, Brennan signed a one-year, major league contract with the
San Francisco Giants. Brennan was optioned to the Triple-A
Sacramento River Cats to begin the regular season. ==References==