OAKLAND — MRI results showed Sonny Gray has a muscle strain and inflammation in his right forearm but no structural damage, A’s manager Bob Melvin said Monday night.

That’s relatively good news for the A’s and Gray, who left Saturday’s start after five innings with pain in his forearm and was placed on the 15-day disabled list. Melvin didn’t hazard a guess as to how long Gray will be out. He’s eligible to be activated Aug. 22, but the A’s are sure to practice caution with their No. 1 starter, who is enduring his roughest season as a major leaguer.

Any problem with the forearm for a pitcher raises a red flag for potential larger-scale elbow issues, so Melvin expressed some relief that the MRI found nothing structurally wrong.

“It’s a muscle strain with some inflammation, a little fluid at the top of the forearm,” Melvin said following a 3-2 victory over the Orioles. “We’re not sure how long that’s going to be, but it’s nothing structural. Nothing structural that (suggests) you’d have to have surgery.”

Melvin did not have information on the exact diagnosis for second baseman Jed Lowrie, who also had an MRI and is on the 15-day DL for a bunion on the big toe of his left foot.