MESA, Ariz. -- A's outfielder Jake Smolinski underwent surgery Thursday to repair the labrum in his right throwing shoulder, which could potentially preclude him from game action for the entire season.
The A's don't have a timetable for Smolinski's return, only saying in a release issued Friday that he will be in a sling for the next four weeks, but such a procedure typically calls for upwards of six months of rehab time.
The arthroscopic surgery, performed by Dr. Doug Freedberg in Scottsdale, Ariz., also included the removal of a bursa sac in Smolinski's shoulder.

A's manager Bob Melvin said he touched base with Smolinski following the surgery and sensed the outfielder was relatively upbeat.
"I texted with him a little bit yesterday, and he felt good about it, too," Melvin said. "It's always good to have a positive frame of mind when you head into your rehab."
Smolinski hit .238 with seven home runs and 27 RBIs in 99 games with Oakland last year and came into camp as the favorite to land the fifth-outfielder spot. Non-roster outfielders Alejandro De Aza and Jaff Decker will now battle for the job.
Alcantara continues bid for big league job
Right-hander Raul Alcantara, out of options and thus squarely in the mix for an Opening Day roster spot, allowed two first-inning runs against the D-backs in Friday's 3-2 loss but none thereafter in a 3 1/3-inning start.
Following Chris Owings' two-out, two-run triple, Alcantara set down each of his next six batters.
"I felt completely different," Alcantara said through interpreter Juan Dorado. "After I got the first two outs, I got a little overconfident and started pitching around guys being a little too perfect."
Alcantara struck out one and walked two in the outing, his sixth of the spring. He has allowed eight earned runs across 14 2/3 innings for a 4.91 ERA. The A's will consider him for one of two open rotation jobs -- Jesse Hahn and Andrew Triggs are also in the competition -- or the final bullpen spot.
"I think it's a good thing because I do know I don't have any options," he said, "so it gives me a chance to compete for a job."
A's option three players
The A's optioned three prospects following Friday's game, sending Franklin Barreto, Matt Olson and Chad Pinder to Triple-A Nashville.
Barreto, ranked by MLB Pipeline as the club's No. 1 prospect, continued to impress by hitting .481 in 27 at-bats this spring. The 21-year-old shortstop -- acquired in the Josh Donaldson deal -- has just four games of experience at the Triple-A level but could soon be knocking on the big league door.

"The hope is we see him at some point here this year," A's executive vice president of baseball operations Billy Beane said.
Olson, who will continue to see time at both first base and the outfield, played in 11 games as a September callup in Oakland last year, while Pinder played in 22 games. Pinder will also expand his versatility by getting action in the outfield. Both players hit two home runs this spring.