Triggs finished for season

Oakland’s rotation, in flux much of the month, could have more clarity Sunday after

Jharel Cotton throws a bullpen session that will determine whether he can start Tuesday against the Rays.

The team learned, though, that Andrew Triggs will not be an option the rest of the year. The right-hander, Oakland’s top starter the first six weeks of the season, had surgery to repair his left hip labrum and will not pitch again this season.

Triggs had told The Chronicle this month that if he had the surgery, he would be throwing off the mound in time for spring training. Fellow starter Sean Manaea had hip surgery in June 2013 and was pitching again during instructional league play that fall. Specialist Dr. Marc Philippon, who performed Manaea’s and A’s minor-leaguer

Mark Canha’s hip surgeries, repaired Triggs’ labrum Friday in Vail, Colo.

Triggs was 5-2 with a 2.12 ERA in his first eight starts but was 0-4 with a 9.64 ERA over his final four before going on the disabled list June 10. He threw 651⁄3 innings, 91⁄3 shy of his career high last season with the A’s and Triple-A Nashville.

Cotton has dealt with blister problems on his right hand for several weeks. If he is unable to go Tuesday, Chris Smith is likely to get another start. Opening Night starter Kendall Graveman could be back within a few weeks. Graveman, who is on the DL with a right shoulder strain, threw batting practice at the A’s facility in Mesa, Ariz., on Friday. His next step might be a rehab assignment. Another starter, Chris Bassitt, will be returning in relief as he comes back from Tommy John surgery. Bassitt, who is enthusiastic about working in a relief role for the rest of the season, will throw three innings for Nashville on Sunday, and if all goes well, he could come off the DL soon. Briefly: Utility player Chad Pinder, out with a left hamstring strain the past three weeks, will run the bases Saturday and could go on a rehab assignment if that goes well . ... Reliever Ryan Dull (right knee) is scheduled to throw two simulated innings in Arizona on Saturday.