Erik Bedard, the left-handed pitcher the Mariners hoped would help them reach the post-season, will undergo exploratory shoulder surgery Sept. 26.
A timetable for his return will depend upon what the surgery determine's Bedard's injury to be.
Bedard last pitched July 4, and has tried rehabbing the shoulder since then without notable improvement.
"Surgey was always an option, but our medical staff thought rehabilitation was a better option," GM Lee Pelekoudas said. "Erik saw Dr. Lew Yocumb while we were in Southern Caliornia and the decision was made to have the surgery done.
"I expect to have him back next year, but until we know the extent of the damage, we won't know."
Bedard was acquired in February in a five-player trade with Baltimore that included Adam Jones, George Sherrill and highly touted pitching prospect Chris Tillman.
In 15 starts this season, Bedard went 6-4 with a 3.67 ERA, but injuries to his hip and back cost him games, and after his last game in July, he felt 'discomfort' in his shoulder.