Kirk Gibson will take over the manager’s duties for the remainder of the season and Jerry Dipoto will become interim general manager, Diamondbacks President and Chief Executive Officer Derrick Hall said in a statement on the team’s website.
“We have all been disappointed in the results over the last few years,” Hall said.
Arizona has slumped to a 31-48 record this season, the fourth-worst in baseball. Last year the Diamondbacks finished last in the NL West with a 70-92 mark. The team is currently 15.5 games behind NL West leader the San Diego Padres.
Gibson has been the Diamondbacks’ bench coach since the start of the 2007 season. Dipoto was in charge of scouting as the vice president of player personnel for the past two seasons.
Hinch posted an 89-123 record with the Diamondbacks after being named the fifth manager in franchise history on May 8, 2009.
Byrnes became general manager on Oct. 28, 2005. The Diamondbacks compiled a 349-378 record during his five seasons and won the NL West Division with a league-best 90-72 mark in 2007 before advancing to the League Championship Series.