Francisco Alvarez took another step in his comeback from his April surgery to repair a torn ligament in his left thumb by taking batting practice for the first time.

“I feel like a baseball player,’’ Alvarez said after the session on the field before the Mets lost to the Giants, 7-2 in 10 innings, on Saturday at Citi Field.

Alvarez said he was swinging at full strength despite still wearing a splint on the thumb that prevents it from fully stretching out, noting, “I hit the ball 115 [mph].”

The Mets expect to have Alvarez back behind the plate at some point before the end of June, but the catcher didn’t rule out an earlier return.

“If I keep feeling good, if I don’t feel anything in my thumb and my body feels good, maybe a couple weeks,” Alvarez said.

But he has several steps to go before that can become a reality.

He’ll see pitches off the high velocity machine, take live batting practice off a pitcher going at full speed and catch a bullpen session prior to beginning a minor league rehab assignment.

Alvarez added he’s talked to Kansas City catcher Salvador Perez, who underwent a similar procedure to his left thumb two years ago.

Perez told Alvarez to take his time coming back and to be careful with the injury when hitting.

Still, Alvarez remains encouraged, saying, “Everything feels normal.”

Brett Baty had been out of the lineup since Monday — as the Mets went with the hot-hitting Mark Vientos — but Carlos Mendoza said he wanted to see Baty’s left-handed bat against right-hander Jordan Hicks.

While Baty whiffed twice against Hicks, he hit one out off right-hander Sean Hjelle with one out in the bottom of the seventh for his fourth homer of the season.

“That homer was huge,” Mendoza said of Baty, who also drew a walk. “It put the team ahead. [The swing was] a lot better, even though he chased early in the game.”

Baty entered in a 3-for-33 rut with 15 strikeouts.

Mendoza indicated Baty would be in the lineup again Sunday, with the Giants starting another right-hander, Logan Webb, but the manager made it clear Friday that they would not keep Baty and Vientos on the roster indefinitely, so a decision will come soon.

Mendoza said David Peterson (hip) had no issues after what could be his final rehab start on Friday.

If the lefty doesn’t report any problems, it’s likely he could slide into the rotation, perhaps in Adrian Houser’s place, with Houser potentially going back to the bullpen.

Tylor Megill and Jose Quintana are slated to start Monday and Tuesday, respectively, against the Dodgers.

“We’ll see how the next days unfold,’’ Mendoza said of Peterson. ‘’Everything is pointed in the right direction.”

The Mets acquired infielder Pablo Reyes from the Red Sox for cash.

Reyes, 30, has spent part of six seasons in the majors and was somewhat productive with Boston a year ago, but has just a .451 OPS in 64 plate appearances this season.

Brandon Nimmo was in the lineup Saturday and went 1-for-5 with four strikeouts after being drilled in the head Friday night, when he stayed in the game thanks to the ball hitting the ear flap attached to his helmet.

“We dodged a bullet there,’’ Mendoza said.

Saturday marked the second time this season Luis Severino took a no-hitter into the sixth inning.

He also threw seven no-hit innings against the White Sox on April 29.