PORT ST. LUCIE — Jeff McNeil is entering spring training as a left fielder — and the Mets’ primary one, at that.

In clarifying his plan on Thursday, manager Mickey Callaway said it’s expected McNeil’s outfield use will be limited to left field, and that McNeil would be the starter against most right-handed pitching.

Brandon Nimmo would play center field and Michael Conforto would play right in such instances.

Juan Lagares and Keon Broxton are the Mets’ other outfielders. Callaway indicated McNeil could start games in left field and move to second base as a defensive replacement for Robinson Cano in later innings. Lagares and Broxton are both plus defenders who would be expected to bolster the outfield in late innings when McNeil starts.

“A majority of [McNeil’s] playing time is going to come in the outfield,” Callaway said. “We are going to want to get him as comfortable as possible out there, so he can concentrate on those at-bats when he’s up at the plate, and we want to see him out there. Most of his playing time in spring training will be in the outfield.”

Among the possibilities the Mets may consider is carrying three catchers to begin the season, according to Callaway. Last week the club signed Devin Mesoraco to a minor-league deal, giving the Mets depth behind Wilson Ramos and Travis d’Arnaud. Tomas Nido is fourth on the depth chart.

Mesoraco received strong reviews for his handling of Jacob deGrom last season. The Mets acquired the veteran catcher in a trade with Cincinnati for Matt Harvey.

“[Mesoraco] made us a better team last year,” Callaway said. “He came in and was prepared every single day, and that rubbed off on our catchers, rubbed off on our pitchers — they trusted him because of those things, and he’s a leader and that showed behind the plate. He caught the majority of a Cy Young season last year.”

DeGrom was named the Mets’ Opening Day starter for March 28 in Washington. The start in an opener will be deGrom’s first. Last season Noah Syndergaard received the honor after deGrom was pushed back in spring training because of back stiffness.