Herrera would sign his first professional contract with Monterey Bay in the 2022 season. His first career start came in the club’s inaugural home opener, where he would record his first professional clean sheet and the first-ever clean sheet in Monterey Bay history. Herrera would play a total of seven games in the 2022 season.
Herrera started 18 matches for the Western Conference side in the 2023 season. In those games, Carlos compiled an 8-7-3 record and kept two clean sheets. Herrera also saw a jump in his save percentage from the previous year, from 65.1% to 48.3% in 2022.
In the 2024 season, Herrera started nine matches, eight of which came in the home stretch of the season. He kept three clean sheets for the season and two in back-to-back weeks in September. In September, Herrera was the starting goalkeeper when Detroit City traveled to Monterrey. He made three saves on five shots as Detroit City took home a 2-0 victory. This past season marked his best professional career save percentage, posting an 81.4% win percentage.
