The A's fired a manager during the season for the first time in a quarter century on Thursday, letting Geren go after four-plus seasons and bringing in former Arizona and Seattle skipper Bob Melvin for the rest of the season.
"It felt like at this point a change was necessary," Beane said. "It got to the point where the emphasis was on the status of the manager on a daily basis and no longer on the field. When that starts to happen, you need to shift the focus to what's really important, which is performance. That's how we came to this decision."
Geren's tenure in Oakland was marked by numerous injuries, a lack of offense, questions about his communication skills and high-profile departures as he was unable to post a winning season after taking over an AL West championship team from Ken Macha.
Geren posted a 334-376 record, including a 27-36 mark this season that has left Oakland eight games behind Texas in last place in the AL West.
The A's currently have four starting pitchers on the disabled list, including a season-ending shoulder injury for Dallas Braden. Oakland also was without injured All-Star closer Andrew Bailey for the first two months and is last in the American League with just 223 runs through the first 63 games.
"Bob Melvin will inherit some of the challenges that Bob had," Beane said. "Bob lost four starting pitchers in the space of three weeks. That was a tough body blow for the team. That was very difficult from Bob's standpoint."
Melvin, 49, took the helm for the series opener in Chicago against the White Sox on Thursday night. He posted a 493-508 record in seven seasons as manager with Seattle and Arizona. He led the Diamondbacks to the NL West title in 2007 and also won 93 games in his rookie season with the Mariners in 2003.
Melvin was also on Bob Brenly's staff as bench coach in 2001 when the Diamondbacks won the World Series and the following year when they won the NL West. Melvin also coached for Milwaukee and Detroit.
He was fired by the Diamondbacks 29 games into the 2009 season, but got another chance when Beane decided it was time to let Geren go.
"This is a difficult situation," Melvin said. "It was difficult for Billy. It's going to be difficult for everybody involved here. It came together so quickly because we've know each other for so long and have so much respect for each other, know what the other one's strengths are."
Melvin played 10 seasons in the majors as a catcher with Detroit, San Francisco, Baltimore, Kansas City, Boston, the Yankees and White Sox. He batted .233 with 35 homers and 212 RBI in 1,955 career at-bats.
Melvin, a Bay Area native, spent time with the Giants in the majors and now gets to manage the A's.
"It's a dream come true," he said.