The Mariners issued a statement Tuesday saying exploratory arthroscopic surgery, scheduled for Sept. 26, will be performed by Dr. Lewis Yocum, who is expected to remove any unhealthy tissue of foreign material from the labrum in the shoulder.
Bedard said the shoulder first started bothering him early in the season, just before he went on the disabled list with a hip problem, according to the Seattle Post-Intelligencer.
"The start after I hurt my hip, I felt discomfort in the last inning I pitched," Bedard said, according to the report. "I know exactly when I did it. After that it got worse and worse."
Mariners vice president Lee Pelekoudas said Bedard decided on the operation after two months of unsuccessful efforts to rehabilitate the shoulder. The right-hander was placed on the disabled list July 10, retroactive to July 5, and underwent an MRI exam on July 22.
"We knew what it was after the MRI -- it's a tear in the labrum and a cyst," Bedard said, according to the newspaper report. "Surgery was always an option, but you want it to be the last option. You're never 100 percent sure what will happen in surgery."
Bedard, obtained from the Baltimore Orioles in an offseason trade that sent five players to Baltimore, last started for the Mariners on July 4 against Detroit, going five innings for the win.
"I didn't say anything [at the time]," Bedard said, according to the report. "Like everybody else in the game, I stopped pitching when I couldn't handle the pain. After my last start, I couldn't lift my arm."
Two months of rehab activities didn't improve matters, leaving Bedard and the Mariners no other choice.
"Erik explored all the opportunities to throw, and he wasn't feeling good enough that he could get on the mound and pitch," Mariners manager Jim Riggleman said after a 6-3 loss Tuesday at Kansas City. "This [surgery] was the last option, and we're going to take this option to see if we can get him ready for next year."
Bedard was 6-4 this season with a 3.67 ERA. His major league career record is 46-38 with a 3.81 ERA in five seasons.
"If you've got something in your arm that's barking and impeding you from firing the way you'd like to, and it's just not getting any better, you just have to do what he's going to do, and that's get it fixed," Riggleman added. "He tried for a month or more, we shut it down and then he tried some more. Some days were better than others, but nothing close to what it's going to take to pitch in a major league ball game."
The Mariners are expecting Bedard will likely miss the start of 2009, but will return to the rotation at some point during the season.
"The surgery we're talking about can be six to nine months [of rehabilitation], or it can be longer," Bedard said, according to the Post-Intelligencer. "To not be able to pitch, that's the most frustrating part of the whole season. To not be able to do what you love is hard."
Information from The Associated Press was used in this report.