Texas Rangers starting pitcher Corey Kluber
Tim Heitman-USA TODAY Sports

Texas Rangers starting pitcher Corey Kluber will be shut down for at least a month after suffering a grade 2 tear of his his teres major muscle during his start on Sunday.

The 34-year-old righty exited his first regular-season start with the Rangers after one inning due to a shoulder injury. After undergoing further evaluation on Monday morning, the team discovered the extent of the damage in Kluber’s pitching shoulder.

Corey Kluber suffers shoulder injury, won’t return as starter this season

Texas acquired Kluber this offseason hoping the two-time Cy Young Award winner would rediscover his form. Instead, the durability issues that plagued him in 2019 returned and his status for the rest of the 2020 season is in jeopardy.

Kluber pitched a shutout inning on Sunday before walking off the mound and complaining of discomfort in his right shoulder. Tests determined that he suffered a grade 2 tear of his teres major muscle, which is located below the armpit and is considered a medial rotator.

A three-time All-Star and two-time AL wins leader, Kluber made only seven starts this past season. He was sidelined for a majority of the year with a right ulna fracture in May and was later shut down in August by an oblique strain.

Due to MLB’s shortened 60-game scheduled, Kluber will not have enough time to return as a starter even in the best-case scenario. Instead, the Rangers can only hope he is able to pitch by September and could be an effective arm out of the bullpen.