SEATTLE (AP) - Seattle Mariners pitcher Erik Bedard, out since July with a tight left shoulder, has decided to undergo surgery Friday.

The Mariners issued a statement Tuesday saying exploratory arthroscopic surgery will be performed by Dr. Lewis Yocum, who is expected to remove any unhealthy tissue of foreign material from the labrum in the shoulder.

Mariners vice president Lee Pelekoudas says 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.

"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 6-5 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."