Uehara, on the disabled list with a strained left hamstring, is going with the team on its West Coast swing to Seattle and Oakland this week and should throw one more time. Trembley said he won't go on a rehab start, but the O's hope he'll be ready on June 10 when Baltimore hosts Seattle.
"He'll throw another sideline [session], not sure how many days from today," Trembley said before Sunday's series finale with the Tigers. "If all goes well, [June 10 is] when he would pitch."
Trembley said that the rest will help Uehara (2-3), who went on the disabled list on May 27. He's already thrown 50 2/3 innings this year after throwing 89 2/3 last season in Japan, and Trembley said the rest could be a good thing for Uehara.
"I think it's advantageous to him," Trembley said. "I think it's still a process for him of being in a five-day rotation. I think he prefers the six- or seven- [day rotation]. We're trying to do everything we can to make sure that he can pitch in August or September."
Trembley said the Orioles are trying to be "very smart" about how they use Uehara, especially since he's adjusting to that different rotation schedule.
Trembley also said that relief pitcher Dennis Sarfate will begin a throwing program Friday. Sarfate's been on the disabled list since May 2.
The return of Uehara will present the team with an interesting decision. The O's have called up rookies Jason Berken and David Hernandez this week to fill holes caused by injuries and other problems.
The question is who would go back to the Minors when Uehara is ready again. Trembley said the team is just going to let the young pitchers go out there and see what happens.
"We've got time," Trembley said. "Let's watch, let's evaluate, let's run them out there, give them opportunities, and then when Koji's ready, then we'll make a decision."
Another note on a young player -- Matt Wieters was in the lineup Sunday, but as the designated hitter. Trembley said it would be a little bit of a break for Wieters, who caught the last two games.
Jeff Seidel is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.