PHOENIX -- Kevin Towers appeared to have a tenuous hold on his job as Arizona's general manager when the Diamondbacks hired Tony La Russa to run their baseball operations.

Though the Hall of Fame manager said he was going to evaluate the entire organization, it seemed only to be a matter of time before the reins were taken away from Towers.

The change came on Friday, when Arizona fired Towers in the midst of a third straight disappointing season, less than four months after La Russa was named chief baseball officer.

"Over the past three months, I have had the opportunity to evaluate all aspects of our baseball operations and have decided to restructure our staff in order to improve our decision-making process," La Russa said. "I have the utmost respect for Kevin and a friendship with him that dates back many years which has allowed me to appreciate his talents and experience."

Towers was hired in 2010 after 14 seasons as the San Diego Padres' general manager. He had almost immediate success, pulling off all the right moves to help Arizona win the 2011 NL West crown, its first division title since 2007.

Since then, Towers' moves haven't paid off quite as well and the Diamondbacks have suffered, following a pair of .500 seasons with a nosedive this year.

Plagued by injuries and subpar seasons from players it had counted on, Arizona lost 22 of its first 30 games to plummet into last place and never really recovered, entering Friday night's game at 59-81 -- 11½ games behind the first-place Los Angeles Dodgers.

Towers said La Russa told him he wanted to restructure the front office a couple of weeks ago and was offered another position within the organization. Towers plans to stay with the organization at least until the Diamondbacks hire a new general manager and will make a decision about his future once he knows who the new person will be.

La Russa said Dave Stewart, a pitcher under La Russa with the Oakland Athletics, and St. Louis farm director Gary LaRocque are on Arizona's list of potential replacements. He also has talked to Diamondbacks scouting director Ray Montgomery, and asked permission to speak with New York Yankees assistant GM Billy Eppler and Los Angeles Angels scouting director Hal Morris.

"When I took this job in 2010, we wanted to win a World Series and we won very early here, set high standards for ourselves," Towers said. "Since 2011, we haven't met the standards that we hoped, ownership had hoped for and our fan base hoped for, and ultimately I'm going to be held accountable for that."

Towers was known as a dealer during his time in San Diego, putting together teams that won four division titles and went to the 1998 World Series. He was fired in 2009 and, after a stint with the New York Yankees, was hired by the Diamondbacks to replace interim GM Jerry Dipoto.

With manager Kirk Gibson at the helm, Arizona had a dramatic turnaround in 2011, winning 94 games and the NL West after losing 97 games the season before.