ATLANTA -- If the Mets could take any whiff of optimism from their 5-1 loss to the Braves on Tuesday, it was the image of Francisco Lindor appearing in the on-deck circle with two outs in the ninth.

For much of the game at Truist Park, Lindor stayed warm, swinging a bat in an indoor cage to see how his body would tolerate that activity. Lindor hasn’t been a regular player for the Mets since Sept. 13, when he injured his back in a game in Philadelphia, and he hasn’t appeared in any part of a game since Sept. 15.

In recent days, he’s begun describing his injury in more graphic language. Lindor recently revealed that he underwent a facet joint injection as part of his treatment.

But he’s also felt less and less discomfort with each passing day. By the ninth inning Tuesday, Lindor felt well enough to ask manager Carlos Mendoza for an at-bat. Mendoza later confirmed that if Tyrone Taylor’s spot had come up in the order, Lindor would have pinch-hit to make his first appearance in nine days.

If nothing changes for the worse, Lindor is “in play” to return to the starting lineup on Wednesday, Mendoza added.

“He was good enough to play today,” the manager said.

The Mets still don’t know exactly what’s causing Lindor’s back pain, only that it’s been severe enough to prevent him from taking the field. Initially, team trainers diagnosed Lindor with spasms, the product of an awkward play around the second-base bag on Sept. 13. A subsequent MRI and CT scan revealed no structural damage, but continued pain in the area prompted Lindor to hang back in New York and receive a bone scan during the team’s off-day on Monday. That, too, showed nothing amiss, underscoring that this is a pain-tolerance issue for Lindor.

So long as he feels well enough to play, he can play.

“The MRI showed no structural damage. It’s just pain,” Lindor said. “So then we went to get into, ‘Let’s check out the bones,’ and there’s no damage to them. So for me, it’s just pain. I’ve just got to find a way to let go.”

To that end, Lindor spent his pregame hours going through a host of baseball activities, including baserunning drills and batting practice. He ran at a relatively high intensity and even hit multiple balls into the Chop House seating area behind the Truist Park right-field wall. But Lindor also spent time wearing an extra-large heating pad around the clubhouse and describing in detail the discomfort he was feeling.

Weather could play a role in his return, as the Mets and Braves are likely to play in wet conditions Wednesday if they’re able to play at all. That could delay Lindor’s return out of an abundance of caution, even if he continues to feel better.

All the Mets know is they’ll be eager to have their MVP candidate back whenever he’s able to make it happen.

“It would be great. It would be amazing,” teammate Brandon Nimmo said. “I would love to see him be able to be himself. That’s going to be the big tell -- is if he’s himself or if he’s playing through some pain or what it may be. … I just want him to do what’s best for him, because that will be what’s best for us. If he got out on the on-deck circle, then I have all the faith that he felt good enough to get out there.

“He’s an MVP-type player, and we would love to have that. But also, we have to kind of prepare like we’re not going to.”