Ramirez, a two-time All-Star, had an MRI after he exited in the first inning of Saturday’s game against Kansas City after fouling off a pitch.
There is no immediate timetable for his return.
The injury could be a blow to the Indians’ playoff hopes as they try to catch the first-place Minnesota Twins in the AL Central.
Manager Terry Francona said Ramirez, 26, has been dealing with a sore wrist, but the injury occurred in a different area of the joint.
Ramirez is batting .254 with 20 homers and 75 RBIs in 126 games this season.
The injury is latest obstacle for the Indians. Two-time Cy Young winner Corey Kluber has been out since May 1 with a broken arm, and starter Carlos Carrasco is being treated following a leukemia diagnosis.
Utilityman Mike Freeman replaced Ramirez in Saturday’s game and had two hits and an RBI.
The Indians called up infielder Yu Chang from Triple-A Columbus.
The Associated Press contributed to this report.