Yankees reliever Michael King instantly knew something was very wrong.

Walking off the mound after a pitch Friday night, the right-hander simply said to manager Aaron Boone: “My elbow.”

Boone’s worst fears were realized Saturday when the valuable member of New York’s bullpen was ruled out for the season with a fractured right elbow. The injury occurred when he threw an 0-2 slider to Baltimore’s Ramón Urías.

“It’s part of baseball, it’s part of sports,” Boone said in the dugout at Camden Yards. “You’re going to face some adversity usually on the injury front that you have to be able to deal with handle and move on from.”

“Right now, we just feel for the person, Michael King, and just how good of a pitcher he’s become, and to see his growth over the last couple of years with us has really been fun to witness. Our heart breaks for the individual,” he said.

King returned to New York on Saturday getting and was getting an MRI/CT Scan to get a clearer picture of the injury. Boone did not know if there was any ligament damage and expected to get more information Saturday night or Sunday.

King was put on the 60-day injured list.

Right-hander Shane Greene was signed and promoted from Triple-A Scranton/Wilkes-Barre. The 33-year-old Greene began his major league career with the Yankees in 2014, was a 2019 All-Star with Detroit and was 1-0 with the Los Angeles Dodgers in one game this season before being released in May.

The 27-year-old King has been a key part of the team with the best record in the majors. He is 6-3 with one save and a 2.29 ERA in 34 games. He struck out 66 in 51 innings.

King has pitched in parts of four seasons for the Yankees, going 9-9 with a 3.84 ERA in 66 games.

“King has been one of the best relievers in all of baseball,” Boone said. “It’s certainly a blow. It’s one that we’ll have to be equipped to absorb. It creates opportunities for other people.”

Yankees star Aaron Judge hit two homers in Friday night’s 7-6 win over the Orioles and leads the majors with 36 on the year. The slugger knew something was wrong as soon as King walked off the mound, saying it was reminiscent of when New York reliever Chad Green had to leave a May 19 game at Camden Yards with right forearm discomfort and later needed Tommy John surgery.

“You try to say a quick prayer and pray for a good outcome,” Judge said. “I saw the same thing happen to Greenie the last time we were here and then to see this happen, it’s never good.”

Said Jameson Taillon, who started for the Yankees: “It was kind of a somber moment in here after the game.”

“He’s a hard worker. I know he’ll get back here and get back to the same spot he was in. It’s never easy seeing a guy walk off the field. You think about his girlfriend and family watching. That’s not easy for anyone,” he said.

Along with adding Greene, right-handed pitcher Clarke Schmidt was called up from Triple-A. Outfielder Tim Locastro was optioned to Triple-A following Friday’s game.