[1] Booser broke his femur during his sophomore year of high school while playing football, requiring knee surgery.

[4] He made his professional debut that same year with the GCL Twins of the Gulf Coast League.

[2][10] Missing baseball, he began to give pitching lessons in 2020, and found that he could throw a fastball at 96 miles per hour (154 km/h).

[5] On August 8, 2022, Booser signed with the Staten Island FerryHawks of the Atlantic League of Professional Baseball, and was traded to the Lancaster Barnstormers the next day.

[14] He made his major-league debut that evening, pitching the ninth inning of the Red Sox 8–1 win against the Pittsburgh Pirates.

[15][16] Booser was optioned to Triple-A Worcester on June 24[17] and recalled to Boston on July 5 after reliever Chris Martin was placed on the injured list.

The Red Sox named him the winner of the Tony Conigliaro Award for the season, which recognizes a "Major Leaguer who has overcome adversity through the attributes of spirit, determination, and courage.