The A’s might be down one of their top relievers for an extended period of time.

After receiving MRI results on Burch Smith’s right forearm on Monday morning, the A’s were relieved to learn that there was no ligament damage. Given the 60-game season, however, a return in 2020 is in serious question.

Smith will refrain from throwing for at least the next two weeks. By the time he’s ready to build up his arm for game action, the A’s likely would be in their final weeks of the regular season.

Regardless of how long it takes for Smith to make it back, A’s manager Bob Melvin looks at the MRI results as a positive. Any ligament damage, which was an initial fear after his fastball velocity dropped from 96 mph to 91 mph Saturday, would have been a severe blow for the 30-year-old Smith, who had Tommy John surgery in 2015.

“It is in the belly of the forearm,” Melvin said. “It’s muscular in nature, to the extent where he’s at least not going to throw a baseball for two weeks. More than anything, we were hoping that the ligament wasn’t involved, and that does not appear to be the case.

“It’s going to take some time before he even plays catch again. Whether or not he pitches again this year, I’m not certain. But I’m really happy we’re not talking about the ligament.”

Smith arrived to the A’s from the Giants in a Spring Training trade as a long shot to make the club, but he has been a revelation out of the bullpen. The right-hander built up a 2.25 ERA over six appearances. Smith did not allow an earned run in his first 11 1/3 innings before the three-run homer by Darin Ruf that preceded his departure from the game Saturday.

Puk increases workload
Pitcher A.J. Puk continues to progress from a left shoulder strain that forced him to the injured list just before the start of the regular season. Puk, ranked by MLB Pipeline as Oakland’s No. 3 prospect, threw all four of his pitches -- fastball, curveball, changeup and slider -- during a 30-pitch bullpen session on Monday at the A’s alternate training site in San Jose. The 25-year-old left-hander will take two days off before throwing another session on Thursday.

Puk likely would pitch out of the bullpen upon returning to the A’s this season. He pitched well in that role last season, when he posted a 3.18 ERA in 10 relief appearances and struck out 13 batters over 11 1/3 innings.