BALTIMORE -- Something has seemed amiss with Jay Gibbons for most of the season, but the Orioles' designated hitter has never let on how much he's been hurting. Instead, he's stoically struggled through the most difficult season of his career.

One day after manager Dave Trembley finally told the media that Gibbons has been dealing with a left shoulder problem, Gibbons elaborated on the extent of the damage Friday.

He said that it's mostly kept him from throwing the ball and that he's not sure how much it's affected him on offense -- if at all. Gibbons, who's had a lost season with the bat, has tried to hide the pain as long as he could.

"I don't make excuses for [hitting]," he said. "Throwing is definitely an issue, [but] I'm not the one that shut me down in the outfield. That's Dave Trembley's decision, and he doesn't want to see me get hurt. I've been available to play the outfield the whole year -- except for Tuesday, because I had the MRI dye shot in my arm the day before."

Gibbons has had all the tests that can be done, including a standard MRI exam and an arthrogram. He wouldn't fully clarify the nature of the injury, but he said there's been a clear diagnosis of an ailment that won't heal on its own. When asked if he'd need surgery to alleviate the problem, Gibbons said, "Only time will tell. Stay tuned."

He was a little more forthcoming about what the tests have showed, but also guarded as to the specific terminology.

"A lot of inflammation, among other things," he said. "When you've been playing on a sore shoulder and playing every day, it's hard to get stuff better. That's just how it is, and it's gradually getting worse."

The injury cropped up a couple months ago, and Gibbons said he hurt himself when attempting to dive for a ball. That's also how he hurt himself last year, when he missed virtually half of the season with a strained left groin and a sprained left knee. Neither of those injuries required surgery, but Gibbons may not have the same luck this time.

The veteran has been held to less than 100 games three times in his six full seasons, and he's at 83 and counting this year. Forty-three of those have come at DH, and Gibbons hasn't played the field since July 29. He's had by far the worst offensive season of his career -- batting .230 with six home runs -- but he's not sure exactly how things will end.

"We'll see. Right now, I'm just taking it every day," he said. "If it gets worse, it gets worse. I'm trying not to worry about it and I hope it gets better. Put it that way."

Starting over: Trembley finally acknowledged an open secret Friday, when he admitted that Brian Burres was moving back into the bullpen and pitching prospect Garrett Olson was moving into the rotation. Olson was recalled from Triple-A Norfolk on Friday and situational southpaw Kurt Birkins was optioned down to the Minors.

"[Birkins will] get the opportunity to start on a regular basis and he's got his foot in the door for next year," Trembley said.

Olson, who went 1-0 with a 3.86 ERA in his first callup to Baltimore, said he expects to be more comfortable this time around. The left-hander said he's still not sure of his status but hopes to stay with the club the rest of the year.

"I'm excited to get out here and get another chance," he said. "I just treat it one day at a time, because you never know if you're going to be here for one more start or if you're going to be here for the long haul.

"That would be nice if I could finish the year here. If not, we'll take it one step at a time."

Olson went 9-7 with a 3.16 ERA in 22 starts at Norfolk, and Trembley said he was pleased with the way he took his demotion in stride. Olson, for his part, freely admitted that he was nervous last time in the big leagues and said he hoped to improve on his performance as soon as he gets the ball.

He'll get his first chance Saturday, when the Orioles play the Red Sox in the FOX Game of the Week.

"Coming back to the ballpark, there were a lot of familiar faces," Olson said. "I kind of had an idea of what I need to do to get back in the zone and I feel a lot more comfortable this time."

The other shoe: Burres, who pitched in relief on Thursday night, will move back to his original role as a swingman and long reliever. He could still move back into the rotation if the Orioles move veteran Steve Trachsel, but for now Burres is back where he's been most effective. Burres has a 5.45 ERA as a starter and a 1.50 mark in relief.

"I respect and appreciate what he's done here," Trembley said. "He's been a great contributor to the club and has done it in a silent and professional way. Right now, the best thing for him and for the organization is him going to the bullpen as a long guy. That's not to rule out that he won't start again, but right now while we have Olson, he'll be a long guy in the bullpen."

Quotable: "I don't know what his arm's going to look like when he's my age, but he makes the ball do some nasty things." -- Trembley, on Boston starter Daisuke Matsuzaka, the front-runner for the American League Rookie of the Year Award

Coming up: Olson will be matched up against Boston's Josh Beckett in Saturday's middle game of the series at 3:55 p.m. ET.