Francisco Alvarez has encouraging rehab outing as he nears Mets’ return

Francisco Alvarez caught seven innings with Double-A Binghamton on Saturday as he gets closer to a potential return to the Mets lineup by the middle of the month.

Carlos Mendoza said prior to Saturday’s 10-5 loss to the Diamondbacks at Citi Field that the 22-year-old’s first rehab game Thursday went well.

Asked if Alvarez might be back by the time the Mets play the Phillies in a two-game series in London next weekend, the manager said, “We’ll see.”

It’s been a fast process so far for Alvarez, who’s been out since undergoing surgery to repair a torn ligament in his thumb in April.

He hit an opposite-field homer in his second at-bat Thursday, but went 0-for-3 with two strikeouts Saturday.

Mendoza added there are still more steps for Alvarez to take before he gets back.

He is slated to catch again Sunday with Binghamton, with an off day Monday, and then another rehab game Tuesday.

“He’s progressing well and in the right direction,’’ Mendoza said. “He’s got to continue to catch, swing the bat, face [more] velo and then build up from seven to eight to nine innings [defensively]. He has to get physically back into baseball shape.”

The Mets have missed Alvarez’s right-handed bat, although he was in the midst of a 5-for-36 skid when he got hurt on April 19.

Mostly led by the combination of Omar Narvaez and Tomas Nido, the Mets entered Saturday with a 0.1 WAR, according to FanGraphs, from their catchers, just 25th in the majors.

The Mets decided not to wait until Alvarez’s return to shake up their catching core, as they designated Narvaez for assignment Friday and replaced him with Luis Torrens, who they picked up from the Yankees in a trade for cash considerations.

Alvarez continues to play with a splint on his left hand, which he figures to do until he’s feeling 100 percent.

Mark Vientos followed up a three-hit game Friday with two more hits Saturday — including a 440-foot solo homer in the fifth.

The performance came after Vientos was given the third-base job following Brett Baty’s being optioned to Triple-A Syracuse on Friday.

“I feel a lot more comfortable [than last year],’’ Vientos said.

“He’s special,’’ Mendoza said. “He’s got power. That ball went a long way. He’s had good at-bats overall.”

Vientos also showed his shaky defense as he bounced a throw to first base on a Eugenio Suarez grounder in the sixth, but Pete Alonso made the scoop.

The battered Mets bullpen is set to get another arm back either Sunday or Monday as Drew Smith is set to be activated off the 15-day IL after recovering from right shoulder soreness.

The return of Smith is especially welcome because the Mets are without Edwin Diaz (right shoulder impingement) and Brooks Raley is out for the year following elbow surgery.

Smith had pitched relatively well prior to the injury, having allowed one earned run over nine innings.

But he’s battled control issues, walking seven in those nine innings.

Mendoza said there was nothing new regarding Kodai Senga’s comeback from his shoulder injury, although the right-hander was on the field prior to Saturday’s game, going through throwing drills.

When asked if there were any plans for Senga to advance to throwing off a mound, the manager said, “As of now, no.”

Francisco Lindor extended his hitting streak to 11 games Saturday. He entered the game 17-for-44 with seven extra-base hits and an OPS of 1.062 over his previous 10 games.

The hot stretch has allowed Lindor to raise his season OPS from .616 to .699. He was removed after seven innings because of the lopsided score, replaced by Jose Iglesias.