Mora was placed on the disabled list on April 15, retroactive to two days earlier, with a strained left hamstring. Trembley said he expects Mora to go on a rehab assignment on Tuesday or Wednesday and then come back when the team goes to Toronto at week's end.
"I'd expect Melvin to play on Friday," Trembley said. "I'd expect Melvin to be in the lineup on Friday."
Trembley said Mora's rehab will likely be just one game.
In addition, Trembley said that the Orioles haven't decided yet if they'll keep the 13 pitchers they're carrying now when Mora returns. Ty Wigginton has filled in at third base during Mora's absence.
Mora had gotten off to a good start, hitting .313 in his first five games, with one homer and seven RBIs. His biggest hit was a grand slam against Tampa Bay on April 11 that helped Baltimore to a 6-0 victory.
The Orioles acquired Mora from the Mets in 2000, and he's become a very popular player in Baltimore. He bounced back from a subpar 2007 to hit .285 with 23 homers and 104 RBIs last year.
Jeff Seidel is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.