After signing, Campusano made his professional debut with the Arizona League Padres. He spent the whole season there, batting .269 with four home runs and 25 RBIs in 37 games.[7] He spent 2018 with the Fort Wayne TinCaps where he slashed .288/.345/.365 with three home runs and forty RBIs in seventy games and was named a Midwest League All-Star.[8][9] Campusano spent 2019 with the Lake Elsinore Storm, earning California League All-Star honors.[10][11] Over 110 games, he batted .325/.396/.509 with 15 home runs and 81 RBIs.[12] He was named California League-co MVP (alongside Luis Castro).[13] Following the season, Campusano played for the Peoria Javelinas of the Arizona Fall League.[14]
Campusano was promoted to the major leagues on September 4, 2020, and made his major league debut that night against the Oakland Athletics, going one-for-three with a solo home run off reliever T. J. McFarland.[15] He was placed on the injured list two days later with a wrist sprain, thus ending his season.[16] To begin the 2021 season, Campusano was assigned to the major league roster before being optioned to the El Paso Chihuahuas of the Triple-A West in late April.[17] In June, he was selected to play in the All-Star Futures Game at Coors Field.[18] Over 81 games with El Paso, he slashed .295/.365/.541 with 15 home runs and 45 RBIs.[19] He appeared in 11 games for the Padres, recording three hits over 34 at-bats.[20]
In 2023, Campusano played in only 7 games for San Diego before being placed on the injured list. On May 12, 2023, it was announced that he would miss at least two months after undergoing ligament surgery on his left thumb.[21] He was activated from the injured list on July 18.[22]
Personal life
Campusano's father, Genaro, signed with the Pittsburgh Pirates as an international free agent in 1989 and spent four years playing in their minor league system.[23]
On October 17, 2020, Campusano was arrested in Grovetown, Georgia and charged with a felony after he was pulled over by police and found to be in possession of 79 grams of marijuana. He was released on a $5,000 bond.[24] The charges against him were dropped in April 2021.[25]