MIAMI — Robinson Cano’s hold on the No. 3 spot in the Mets lineup could be weakening.

The disappointing second baseman was dropped to fifth in the batting order against Marlins lefty Caleb Smith in the Mets’ 8-4 loss Friday, and manager Mickey Callaway said he plans to utilize a “fluid” batting order moving forward.

Cano, who entered play with a .646 OPS, was the Mets’ No. 3 hitter in 56 games before the All-Star break. He batted fifth in eight games.

“I think it’s something that can be fluid,” Callaway said. “We’ve done this before when the lefty is pitching and this is more about the lefty today. We all know Cano has had his struggles on the road and done really well at home, so it’s something I think is going to be fluid and you might see some fluidity with our lineup throughout because we continue to try to put guys in position to win.”

Cano went 1-for-4 with a run scored as Pete Alonso moved from second to third in the lineup and went 0-for-3 with three strikeouts and walk.

J.D. Davis batted second and posted an 0-for-2 with two walks and a run.

“Putting the same lineup out there every day has not worked,” Callaway said. “We might have to mix it up a little bit. I am sure that everybody understands that and winning has to be paramount.”

Jed Lowrie sustained a recent setback in his rehab, according to general manager Brodie Van Wagenen, straining his right calf.

The veteran infielder, who still hasn’t played for the Mets this season after arriving on a two-year contract worth $20 million, had been building up his left side and ramping up his rehab when he sustained the calf strain.

Brandon Nimmo will be evaluated next week as he attempts a return from the bulging disk in his neck.

Nimmo, who last month was shut down for 30 days, has been running and playing catch, according to Van Wagenen.

Wilmer Font was designated for assignment before the game and the Mets recalled pitcher Chris Mazza from Triple-A Syracuse. Font had been effective in low-leverage relief appearances, but Mazza, a 29-year-old rookie, impressed team officials during his first stint with the club right before the All-Star break.

“[Mazza] controlled the running game, he got ahead, he threw strikes,” Callaway said. “He did all the little things we were talking about for our relievers to have success.”

Matt Kemp was released by the Mets in what was termed as a mutual agreement between the player and organization. The veteran outfielder, who was signed in May, played eight games for Triple-A Syracuse.