Bergesen had been attempting to return from a bruised left shin and wasn't progressing as quickly as the team would've liked. Bergesen, who went 7-5 with a 3.43 ERA in 19 starts for Baltimore, probably wouldn't have been able to make it back until the last week of the season, prompting the team to end his year early.
Things are a little different for Tillman and Matusz, who have been healthy all season. The Orioles are determined to be careful with the youngsters and make sure they don't overstrain their arms too early in the process.
"I don't know how many more [starts] they might have," Trembley said. "I have to talk with Andy and get with [pitching coach Rick Kranitz] about that. I think we'll be looking at that further on the off-day on Thursday. But I would say right now that it's probably a maximum of three more starts for those two guys."
That plan applies more to Matusz, who is in his first professional season and doesn't really have much of a track record beyond his college career. Tillman managed to throw a full professional season last year but didn't throw in September, and he talked about feeling drained after coming out of his most recent start.
"Drained physically? Emotionally? Mentally? I don't know," said Trembley. "Both guys are first-year guys in the big leagues and you're looking at innings pitched. ... You're looking at what they threw last year, what they threw this year and reaching a point that a maximum amount of innings they're going to pitch and you shut them down."
Trembley went on to say that he won't limit rookies Jason Berken or David Hernandez down the stretch. Matusz threw 113 innings in the Minors this season and has thrown 30 2/3 more with the Orioles. Tillman, meanwhile, worked 96 2/3 innings at Triple-A Norfolk and has thrown 40 1/3 more for Baltimore in seven starts.
Spencer Fordin is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.