After more than a month off, A.J. Griffin's right forearm and elbow discomfort continues, and Griffin will get a second opinion from Dr. Thomas Mehlhoff in Houston on Tuesday.

Griffin resumed throwing in the past day or two, manager Bob Melvin said, and things still weren't feeling right. Griffin has been out with what has been described as flexor tendinitis, which is often a precursor to Tommy John surgery. Griffin first experienced forearm soreness late last season.

Mehlhoff did Fernando Rodriguez's Tommy John surgery last year, and Rodriguez was back throwing off a mound a year after his ulnar collateral ligament was replaced. He is on a rehab assignment with Triple-A Sacramento and faring well, with a 1.29 ERA in six games. Recovery from Tommy John surgery is typically 12-18 months for a first procedure.

Griffin, 26, was the A's projected No. 4 starter. He is 21-11 with a 3.60 ERA in 47 starts. Oakland's record in his starts is 31-16.