With Felix Doubront going on the disabled list on Opening Night with an elbow injury, it appears as if former Giants left-hander Eric Surkamp will wind up in Oakland’s rotation to start the season.

Surkamp, 28, had an excellent spring, including seven scoreless innings against his old club in relief of Doubront on Saturday. Surkamp has drawn interest from Asian teams, and the A’s would prefer not to lose him should an overseas team try to buy out his deal while he is not on the 40-man roster.

Doubront, who left his outing Saturday after one inning with left forearm tightness, said Monday that surgery has not been ruled out for what the A’s have described as a left elbow sprain. He is going to visit Dr. Timothy Kremchek in Cincinnati for a second opinion Monday.

Trainer Nick Paparesta said that there is some “fibrous tearing” in the ulnar collateral ligament. Fully torn UCLs require Tommy John surgery; sometimes it is possible to rehab partial tears by getting the inflammation out of the area, then doing strengthening work so that muscles provide greater support for the elbow.

Paparesta said the MRI exam “wasn’t definitive, that’s why we’re reaching out for a second opinion.”

Doubront said that he believes he has had a similar issue in the past, missing several weeks in 2010 with something that felt much the same. He already is feeling better, he said.

The A’s sent down the other top candidate for the fifth spot, Jesse Hahn, after a rough spring in which he had an 11.15 ERA. Hahn probably will return to Oakland at some point, but he already is at Triple-A Nashville and is expected to stay there this week. He must remain in the minors at least 10 days unless he replaces a player who goes on the DL, and outfielder Andrew Lambo replaced Doubront on the roster Monday.

Surkamp was 2-1 with a 3.60 ERA, best among A’s starters this spring. By adding him, the A’s would keep two left-handers (along with Rich Hill) in the rotation.

With no need for a fifth starter until Friday, the A’s recalled Lambo. They will go with 11 pitchers instead of their usual 12. Lambo, claimed off waivers from the Pirates in November, went 16-for-48 with two homers during the spring.

Sogard update: Infielder Eric Sogard (neck) has improved to the point that he might hit off Henderson Alvarez when Alvarez (shoulder) faces hitters Wednesday for the first time since his shoulder surgery last year. Sogard might begin a rehab assignment this weekend.

Susan Slusser is a San Francisco Chronicle staff writer.