He spent the 2019 season with the High-A Lancaster JetHawks, pitching to a 5-10 record and 5.81 ERA with 143 strikeouts in 28 appearances.

[5] On April 17, 2021, Gilbreath was promoted to the major leagues for the first time,[6] however he was optioned down the next day without making an appearance.

[7] Gilbreath made his MLB debut that day and pitched an inning of relief, but allowed a home run to the Arizona Diamondbacks' Josh Rojas.

Gilbreath was amongst the best Rockies relievers in his rookie campaign, posting an ERA of 3.38 in 47 games.

On March 7, 2023, it was announced that Gilbreath would undergo Tommy John surgery, ending his season before it began.