[8] Prior to the 2020 season, Cowser was named to the Golden Spikes Award watch list alongside earning pre-season Southland Conference honors.

[14] On August 2, 2021, Cowser made his professional debut with the Rookie-level Florida Complex League Orioles, hitting a solo home run in his second at-bat.

In the 6th inning of the contest, Cowser recorded his first major league hit, an RBI single off reliever Nick Ramirez.

[26] He spent the remainder of the campaign with the Tides after being optioned for a second time on September 3 when Aaron Hicks was reinstated from the injured list.

[27] Cowser received the Most Valuable Player (MVP) Award at the Triple-A National Championship Game won by the Tides over the Oklahoma City Dodgers 7–6 on September 30.

[31] He had another four-RBI performance when he hit the first two home runs of his MLB career in a ten-inning 9–4 victory over the same opponent two nights later on April 11.

On October 2, 2024, Cowser was forced to exit Game 2 of the Wild Card Series against the Kansas City Royals an inning after taking a pitch off the hand while swinging.

[34] He served as the master of ceremonies of the 2025 Major League Baseball draft lottery at the Winter Meetings on December 10, 2024.