Bud Black, the second longest-tenured and winningest manager in Padres history behind Bruce Bochy, was fired on Monday in the midst of his ninth season with the team.
The club announced it will begin a search for an interim manager for the rest of the 2015 season.
Bench coach Dave Roberts, a former Padres outfielder, was named to serve as manager when the Padres host the Oakland Athletics on Monday night.
The Padres entered the season expecting to contend in the National League West with a roster that was overhauled in the offseason. San Diego is 32-33 and in third place in the NL West heading into Monday’s game.
Black, 58, had a 649-713 record during his tenure, with only two winning records. He began managing the Padres in 2007 and delivered an 89-74 record in his first season when San Diego lost a one-game playoff to the Colorado Rockies to determine the NL wild-card team.
In 2010, the Padres were in contention until the final game of the season, finishing just one game behind the San Francisco Giants. The Padres went 90-72.
The Padres finished in third place in each of the past two seasons in the NL West.