David Stearns identified the club’s No. 1 trade deadline need as bullpen help.

The Mets president of baseball operations will seek external additions.

“If that doesn’t happen for some reason,” Stearns stated on Monday, “then we’ll likely need to start considering some of the Triple-A pitchers and assess whether those players can eventually bolster our bullpen.”

Among these pitchers are starters Brandon Sproat and Nolan McLean, who are not yet seen as ready for major league relief roles but could potentially make their way into the bullpen as the season reaches its critical juncture.

Sproat and McLean are top starting prospects who are performing well enough with Triple-A Syracuse to be considered for promotions.

Sproat, after a rocky start to his season, has managed to pitch 23 consecutive innings without giving up an earned run. McLean has showcased more stability, achieving a 2.58 ERA over 17 appearances with Syracuse and Double-A Binghamton this season.

The Mets rotation, which had been racked by injuries earlier in the season, now is healthy.

Stearns signaled the Mets did not want to convert minor league starters into relievers before being sure they would not be needed as rotation depth.

“The challenge with [converting] in-season is once you do that, you can’t reverse yourself in the same season,” Stearns said before the Mets opened a series with the Angels at Citi Field. “… Once we shorten someone up to give them a chance to be a member of our pen, really tough to build them back up if you need them as a starter. And so we want to be very cautious if we’re going to entertain that.”

While with the Brewers, Stearns tried top starting prospects such as Corbin Burnes and Freddy Peralta out of the major league bullpen as a way to shoehorn their strong arms onto a roster. Such a tactic with the Mets is at least an option.

It is also possible that Sproat and/or McLean will be called up to plug a hole in the rotation.

And it’s also possible that the two spend their seasons in the minors. Stearns said he does not feel pressured to call them up at some point this season, but he is happy with their progress.

“Both those guys, I think over the last three weeks, have taken meaningful steps forward in their development,” Stearns said. “I’m excited to see where it goes from here. And if there is a need, I think either of those guys could be ready over the next couple months.”

Starling Marte could return in a “couple of days” manager Carlos Mendoza said, perhaps Wednesday in the series finale or Friday in San Francisco.

Marte is running up to 90 percent and is hitting off a machine. The Mets do not think he will require a rehab assignment.

“He’s getting close,” Mendoza said of Marte, who has been out since July 6 with a right knee bruise.

José Buttó also should be back soon after a third rehab outing Sunday, in which he threw another scoreless inning with Syracuse.

Mendoza was not sure whether Buttó, who has been out with an illness, would need a fourth rehab game or would be activated Wednesday.

Paul Blackburn (right shoulder impingement) has been sent to Syracuse, where he is expected to make his second rehab start Tuesday.

The Mets reclaimed righty Rico Garcia, who had pitched one game with the Yankees before being designated for assignment.

Garcia had spent the season in Syracuse before pitching in two games with the Mets early this month.

Richard Lovelady cleared waivers and was outrighted to Syracuse.

Dedniel Núñez, who will miss the season with elbow surgery, was transferred to the 60-day IL.