PHOENIX — Michael Conforto’s free agency will spill over into next offseason.

The former Mets outfielder underwent surgery on his right shoulder last week that will keep him sidelined for all of 2022, according to agent Scott Boras. The Post recently reported that Conforto had been given the option of surgery. The Post’s Jon Heyman first reported Saturday that Conforto underwent the surgery by Dr. Neal ElAttrache.

Conforto sustained the injury in January during workouts, according to Boras. After the lockout concluded Conforto remained unsigned as he attempted to rehab the shoulder.

Last offseason Conforto declined the Mets’ qualifying offer for this year worth $18.4 million as he pursued a larger deal. If Conforto signed elsewhere, the Mets would have recovered a draft pick in the No. 75-80 range overall.

But Conforto’s continued unemployment into next winter means the Mets will not receive that compensatory draft pick.

“You don’t want any of your friends or teammates to undergo surgery, especially as serious as a shoulder surgery,” Pete Alonso said after the Mets’ 5-2 loss to the Diamondbacks. “I wish Mike all the best and speedy and healthy full recovery.”

Taijuan Walker’s return to the Mets’ rotation will likely occur against the same opponent he last faced.

The right-hander is expected to come off the injured list and to start Friday or Saturday against the Phillies on the next homestand, according to manager Buck Showalter. Walker departed after just two innings on April 11 in Philadelphia with shoulder soreness that was diagnosed as bursitis.

Team officials are still deciding whether Walker will throw a simulated game Monday in St. Louis or if he will need another minor league rehab start before rejoining the rotation. Walker pitched in a minor league rehab game on Wednesday.

By holding Walker back until Friday or Saturday, the Mets can keep their rotation in order without disruption in terms of added days in between starts. Max Scherzer, Chris Bassitt and Carlos Carrasco will start the three games in St. Louis. The Mets have Thursday off.

Walker underwent surgery in January to remove damaged cartilage from his right knee. He was lifted early from his final spring training start because of knee discomfort and then departed his start against the Phillies with the shoulder soreness.

Edwin Diaz initially thought the location was good on his slider, which Daulton Varsho hit for a game-tying homer in the ninth inning Friday, but upon further review that wasn’t the case.

“I thought I made a good pitch, but when I saw the video I left it right in the middle,” Diaz said. “I threw 14 pitches and on the bad one they got a homer.”

The blown save was Diaz’s first in only two chances this season. The right-hander’s other five appearances, entering Saturday, had occurred in non-save situations.

Drew Smith’s stock continues to rise. The right-hander has a perfect ERA over seven appearances. He has allowed three hits and three walks with eight strikeouts in seven innings.