Manny Acta will not return as manager of the Cleveland Indians, the team announced Thursday.
Acta, who was hired by the Indians after the 2009 season, has led the team to an AL-worst record of 65-91 this year.
Sandy Alomar Jr. will serve as interim manager for Cleveland's final six games of the season.
"The Cleveland Indians would like to thank Manny Acta for everything he has done for the organization in his three seasons as our manager," Indians executive vice president and general manager Chris Antonetti said. "Manny's passion for the game, positive attitude and tremendous knowledge of baseball helped guide us to a number of high points during his tenure.
"Managerial changes are never easy or taken lightly, but as we approached the end of the season and turned our attention to assessing the year, we determined a change was necessary."
Acta compiled a 214-266 record over three seasons with Cleveland.
Alomar has been a part of the Indians' coaching staff since 2010 and served as the club's bench coach over the last two seasons.
The six-time All Star played 11 seasons with Cleveland (1990-2000) and was inducted into the team's Hall of Fame in 2009.
The team said Alomar will be one of the candidates considered for the managerial position and will start the search immediately.
The rest of the coaching staff will remain intact through the remainder of the season.