Soloff said "there's a high index of suspicion" that Sizemore will need an operation at some point. Soloff, speaking before the last-place Indians hosted the Chicago White Sox on Tuesday night, said Sizemore will have to play with soreness in his elbow for the remainder of the season.
Sizemore would likely have an arthroscopic procedure on his elbow, which has bothered him since spring training. Sizemore has synovitis, an inflammation of the joint lining.
"Grady will have symptoms the balance of the season," Soloff said. "We hope to keep him away from symptoms that affect his performance or put him at risk of injury."
An MRI revealed no structural damage in Sizemore's elbow. Earlier this season, the Indians had Sizemore play some at designated hitter in hopes some rest would help his elbow. They finally had to shut him down and placed the three-time All-Star on the DL on May 31.
Sizemore's elbow has responded well since returning. He missed three weeks with the injury, and the Indians, who have lost 12 of 15, desperately missed their leadoff hitter and offensive catalyst. Sizemore was dropped to No. 2 in the batting order since his return on June 23.
A .279 career hitter, Sizemore is batting .236 with 10 homers and 39 RBIs in 55 games. Since returning from the DL, he's batting .250 with one homer and eight RBIs in six games.