“Obviously it’s going to put him in jeopardy to start the year,” Boone said.
Boone expressed optimism this wouldn’t be a long-term issue but acknowledged that Severino “most likely” would get placed on the injured list.
Severino, 29, went 7-3 with a 3.18 ERA in 19 starts last season. He struck out 112 in 102 innings.
Boone said the issue arose after Severino made his last start on Tuesday.
“Afterwards when he was kind of doing his workout, arm-care stuff, he just felt some tightness in there,” Boone said. “He came in the next day and it was a little tight, and then yesterday he was going to go out and throw and that tightness was still there enough to where he wanted to go get it looked at.”
The Yankees already won’t have right-hander Frankie Montas or left-hander Carlos Rodón for the start of the season.
Rodón, who joined the Yankees by signing a $162 million, six-year contract in the offseason, has a left forearm strain that will cause him to open the season on the injured list. Rodón has been an All-Star the last two seasons, in 2021 with the Chicago White Sox and in 2022 with the San Francisco Giants.