Gasser grew up in El Dorado Hills, California, and attended Oak Ridge High School.
[5] He was assigned to the Rookie-level Arizona Complex League Padres to start his professional career, where he made one appearance before being promoted to the Lake Elsinore Storm of Low-A West.
[6] On August 1, 2022, the Padres traded Gasser, Dinelson Lamet, Taylor Rogers, and Esteury Ruiz to the Milwaukee Brewers for Josh Hader.
[10] He made his first MLB start the same day and didn't give up a run across six innings, allowing just two hits, no walks, and striking out four.
[12] On June 20, it was announced that Gasser would require season–ending surgery to repair the ulnar collateral ligament in his pitching elbow.