Luis Severino will miss the season with an elbow injury that requires Tommy John surgery, and the New York Yankees’ rotation no longer looks all that imposing.

New York announced Tuesday that the 26-year-old right-hander has a partially torn ulnar collateral ligament, a development that means the two-time All-Star will miss all of 2020 after being sidelined for nearly all of 2019.

Mets medical director Dr. David Altchek will operate Thursday in New York.

Left-hander James Paxton already was projected to miss the first two months of the season following back surgery on Feb. 5. Domingo Germán must serve the final 63 games of an 81-game suspension for violating Major League Baseball’s domestic violence policy. He is eligible to return June 5, barring any postponements.

Severino’s injury leaves the AL East favorites with a rotation of newly signed ace Gerrit Cole, Masahiro Tanaka, J.A. Happ and two openings. The usual recovery time for Tommy John surgery is a year or more.

New York won the AL East with a 103-59 record last year, its best in a decade, and lost to Houston in the AL Championship Series.

Severino went 19-8 with a 3.39 ERA in 2018 and was given a $40 million, four-year contract. He was scratched from his first scheduled spring training appearance on March 5 because of rotator cuff inflammation in his right shoulder. The Yankees said April 9 he had strained his latissimus dorsi muscle. He did not make a minor league injury rehabilitation appearance until Sept. 1 and did not make his first appearance for the Yankees until Sept. 17.

Additionally, Giancarlo Stanton will likely miss opening day because of a strained right calf, another significant injury for a team that was beset by health problems last season.

Manager Aaron Boone said Stanton was hurt near the end of defensive drills on Tuesday. An MRI found a Grade 1 strain.

The Yankees put a major league-record 30 players on the injured list last year, with Stanton missing most of the season.

Stanton played in just 18 games due a number of injuries last season, batting .288 with three homers in 59 at-bats. He hit 38 homers in his first year with the Yankees in 2018, one year after a going deep a career-high 59 times in 2017 with the Miami Marlins.

The outfielder/designated hitter signed a $325 million, 13-year contract after the 2014 season.