The Mets have yet to make a decision on whether or not to call up Peter Alonso in September. Manager Mickey Callaway said the slugging first baseman is one of several players the team is considering bringing up once rosters expand.

“We’ve discussed him, the pros and cons of what we’re trying to do with him, not only his year, but in the future,” Callaway said before he Mets blanked the Nationals, 3-0, at Citi Field on Saturday. “He’s definitely a name we’re discussing.”

Asked what the cons would be about promoting Alonso, who has produced 32 home runs, 109 RBIs and .952 OPS for Double-A Binghamton and Triple-A Las Vegas, Callaway pointed to the former second-round pick’s mediocre defense.

“It’s not just about swinging the bat here,” the first-year manager said. “It’s about defense as well. We want to make sure he’s in a good spot in his overall game and the things we’re going to value in this organization moving forward.”

The other issue in calling up Alonso, who is only a first baseman, is where he would play. On Friday, Callaway said the Mets were going to give veteran Jay Bruce a lot of time at first base, to determine if he could be an option here next year. Bruce will start at first on Sunday, Callaway said, after he played right field Friday and Saturday.

Aside from Dominic Smith, Callaway declined to name any other players who would get the call, though he said the team has a good idea of which prospects it wants to get a look at.

“I think it’s going to be a fun September,” he said. “Some of our young players deserve a chance.”

David Wright continued his rehabilitation assignment with Single-A Port St. Lucie and went 2-for-4 with a double and an RBI. He played seven innings at third base.

Brandon Nimmo (left index finger) also played for Port St. Lucie and went 1-for-3 with a stolen base and run scored in seven innings in center field. Callaway said Nimmo would play against on Sunday for the Single-A team and then be re-evaluated.

Catcher Devin Mesoraco’s sprained neck is improving, Callaway said. It’s at the point, the Mets believe he could catch an inning or two if needed, but he still can’t swing a bat. The Mets have opted not to place him on the disabled list.

Mesoraco left Thursday’s game with neck stiffness after he was charged with a passed ball that allowed the Giants to score an unearned run against Jacob deGrom.

Tomas Nido was recalled from Binghamton to give the Mets an additional catcher on the roster because of Mesoraco’s iffy status and the fact Kevin Plawecki’s wife Tayler is due to give birth on Monday.

Rookie Jeff McNeil singled twice to extend his hitting streak to 10 games. He’s batting .474 (18-for-38) in that stretch and has hit safely in his past 12 starts.