Jeff McNeil could be back with the Mets from his left hamstring strain as soon as Saturday, but Mickey Callaway said he hasn’t decided exactly who will wind up missing the most playing time when he returns.

“It’s really hard to say,’’ the manager said before Friday’s 2-1, 14-inning loss to the Braves at Citi Field. “I think we need to take it day by day. Obviously, somebody’s going to get less playing time, but it might be just resting all the guys who are going good. I think that’s important, too, especially in this stretch run.”

McNeil went 1-for-4 in a seven-inning rehab game with Single-A Brooklyn on Friday. He started in right field and moved to third base at Norwich a day after he got just one at-bat due to bad weather with Triple-A Syracuse at Lehigh Valley.

Callaway said lack of action in Thursday’s rain-shortened game might lengthen McNeil’s rehab stint, but he will be back in Queens soon enough, playing third, second, left and right, according to the manager.

“You put McNeil in there, you’re not losing anything defensively or offensively, so we can continue to put a potent lineup out there and a solid defense — and also rest guys a little more,’’ Callaway said. “We’ve been leaning on guys.”

Callaway referenced Todd Frazier’s absence from Friday’s starting lineup against right-hander Mike Foltynewicz as a blueprint for how he hopes to give regulars days off as the Mets try to make a late push to the postseason. Frazier entered as a pinch hitter in the eighth and went 0-for-2 with a strikeout.

“It’ll be a mixture of everybody,’’ Callaway said.

Brandon Nimmo (neck) played center and went 0-for-4 in a rehab game for Triple-A Syracuse on Friday.

Tomas Nido was drilled in the back of the head by Josh Donaldson’s backswing in the sixth.

He initially stayed in the game after being checked out by trainers, but was replaced by Wilson Ramos to start the seventh. Rene Rivera was also removed from Triple-A Syracuse’s game and could be a replacement if Nido ends up on the injured list.

“He felt fine, finished the inning, came in and got evaluated and wasn’t feeling as good, so we got him out,’’ Callaway said.

Nido will be reevaluated Saturday.

“He got hit hard,’’ Jacob deGrom said. “I was walking up there [to him] and didn’t know what to do. He was obviously in some pain. He seemed OK once he got up.”

Ramos extended his hitting streak to 17 games with a single in the 10th inning.

Mets’ pitchers set a franchise record — and tied an MLB mark — by striking out 26 batters on Friday. The Mets’ previous record was 24, set on June 2, 2018, against the Cubs in another 14-inning game.

Robinson Cano took batting practice and ran the bases Thursday, but still doesn’t have a timetable for his return.

“I don’t have a time to come back,” Cano said Friday.

The second baseman added, “I feel good. I still have to do a lot of stuff.”

He wouldn’t make any predictions as to whether he’ll see the field again in 2019.

“I don’t know,” Cano said. “We’ve got to do a lot of things. … I’ve got to keep training, strengthening my hamstring, keep doing exercises.”

Cano’s absence has been made up for in part due to Joe Panik’s success since signing with the Mets.

He went 13-for-38 with 10 runs scored and a pair of walks in his first 12 games with the Mets before going hitless Friday.

The Mets signed former Yankee Nick Rumbelow to a minor league contract. The right-hander is slated to head to Triple-A Syracuse after most recently pitching with the Sugar Land Skeeters in the Atlantic League following his release from the Mariners earlier in the season.

Rumbelow, 27, pitched in just three games with Seattle this year. He appeared in 17 games with the Yankees in 2015 after being drafted by the team in the seventh round in 2013.

— Additional reporting by Zach Braziller