Perlozzo's firing was disclosed by a person with knowledge of the situation who spoke to The Associated Press on condition of anonymity because no announcement had been made. The Orioles scheduled a news conference for later today.

Bullpen coach Dave Trembley, who has served as a minor league manager in the organization, will be the interim manager when the Orioles begin a six-game trip in San Diego tomorrow.

Perlozzo was victimized by an underachieving bullpen and a punchless offense that ranks last in the AL in home runs. Baltimore was 27-27 and second in the AL East on May 31 before losing 13 of 15, including the final eight games of a 1-8 homestand that ended Sunday.

After Sunday's 6-4 loss to Arizona on Sunday, there was talk in the clubhouse of Perlozzo's imminent dismissal. Several players publicly defended him, including Kevin Millar, who called for a players-only meeting in San Diego on Tuesday.

"Sam Perlozzo doesn't throw the ball and doesn't catch the ball. We know that for sure, right? He doesn't hit the ball," Millar said. "He doesn't play. We play. And we've got to find a way to play better."

Baltimore will seek to do so for another manager. Former Florida Marlins manager Joe Girardi is thought to be one of the leading candidates for the position.

The 56-year-old Perlozzo is the second straight Orioles manager to be fired in midseason. He took over on an interim basis after the Orioles dismissed Lee Mazzilli on Aug. 4, 2005. After guiding Baltimore to a 23-32 record that season, Perlozzo signed a three-year contract in October 2005.

He finished 122-164, including 70-92 last season and 29-40 this year.