"A lot of things have happened over the last three, four years that have been completely out of his control. The guy played the game right. He was an elite player in this league. Unfortunately, over the last three or four seasons, he hasn't been able to do it."
Over the past four years, the 30-year-old Sizemore has undergone operations on his back, left elbow and both knees, along with a pair of sports hernia procedures. Most recently, Sizemore had lower back surgery in March.
Sizemore progressed to running and agility drills last week, but head athletic trainer Lonnie Soloff said the center fielder experienced soreness and inflammation in his surgically repaired right knee. The Indians will slow Sizemore's rehab for 10-14 days.
"As a result of this recent development," Soloff said, "and with where we are in the season, it's unlikely that he'll have enough time to see any game-related activities."
Sizemore was signed to a one-year contract with a base salary of $5 million over the winter after hitting just .224 with 10 home runs and 32 RBIs in 71 games a year ago. Over the 2008-2011 seasons, Sizemore hit a combined .234 with 28 homers, 109 RBIs and 17 stolen bases in 210 games.
That is a drastic drop-off from 2005-08, when Sizemore hit .281 with 107 homers, 325 RBIs and 115 stolen bases in 639 games, and he made three All-Star teams, took home two Gold Glove Awards and earned one Silver Slugger.
Acta does not believe that Sizemore, a free agent this coming winter, is facing the end of an injury-shortened career.
"No, I would not be jumping to that conclusion," Acta said. "He's still very young and has plenty of time, I would say, to still heal his body and play baseball. I wouldn't be a guy who'd be erasing this guy completely."