Ryan Weathers left the mound Saturday as a hurting starting pitcher and, if all goes well, likely would return at some point this season as a healthy reliever.

“Big picture, obviously really good news,” manager Aaron Boone said after Weathers’ examinations revealed a low-grade flexor strain, which sent him to the 15-day injured list, but no damage to his UCL.

Smaller picture, the Yankees have lost a thriving piece of their rotation for at least several weeks and likely more, Weathers requiring a shutdown of two-to-four weeks before he can begin building up again and helping “in some capacity” before the end of the season, Boone said.

A forearm injury that briefly raised the specter of Tommy John surgery may instead force the Yankees into a move they were already considering for Weathers.

A day after Weathers exited in the fourth inning with a forearm issue, he said he felt relieved after learning he believes he can still contribute this year — and next. That outlook could have been in serious doubt had his ulnar collateral ligament been damaged, an injury that typically leads to Tommy John surgery.

Weathers dealt with a similar flexor strain last year with the Marlins, causing him to miss all of April and a couple of weeks in May. But Saturday’s scan brought more encouraging news. Weathers said it “was a little better” than last season’s.

“All things considered,” Weathers said from the clubhouse before Sunday’s series finale with the Blue Jays in The Bronx, “I think it was pretty good news.”

That news could fast-track a transition the Yankees might have approved anyway. Weathers has been getting better and better this season, posting a 1.29 ERA over his past six starts after choosing to lead with his offspeed stuff and reduce his four-seamer usage.

But his path to a playoff rotation spot would be difficult. He would likely take a backseat to Gerrit Cole, Cam Schlittler and Max Fried in a playoff series, with Carlos Rodón also ahead of him to a lesser extent.

That reality, combined with Weathers’ experience as a reliever, the Yankees’ thin bullpen and his career-high 137 ⅓ innings, all pointed toward a conversion at some point this season.

There is just one major obstacle: Weathers’ forearm has to cooperate.

“First things first is getting to the point to where he’s in position to start throwing and then hopefully we’re able to build him up smoothly,” Boone said. “Obviously whatever capacity we can get him back, he’s obviously an outstanding pitcher. He can help us in some way.”

For now, the encouraging scan keeps the door open — but what happens next could determine exactly how the Yankees use Weathers when he returns.