The three-time All-Star outfielder, on the disabled list for the seventh time in the last four years, jogged around Progressive Field before Cleveland played the Chicago White Sox on Tuesday. He said he hopes to return in June and hasn't thought about calling it a career.
"I'm not at that point yet," said Sizemore, who had lower back surgery March 1.
"I still feel pretty young and I'm relatively early in my career. I love this game. I've had tough luck with injuries. All you can do with that is try to get healthy."
Sizemore got hurt early in spring training while rehabbing from right knee surgery in October.
The 29-year-old missed only nine games from 2005 to 2008, but has since had hernia surgery and operations on both knees and his left elbow. He played in only 33 games in 2010 and 71 a year ago.
Sizemore wore a protective sleeve on his left calf as he jogged. The herniated disc in his back had caused weakness in his left leg.
"There wasn't any pain in the back, but my left leg lost strength," Sizemore said. "The calf still gets a little tight, so I keep it warm.
"I feel good, but now it is about getting my entire body feeling good. I see myself getting out there and playing next month. I still have a lot of work to do, but I feel like I'm at the tail end of this rehab."
When healthy, Sizemore was one of the most productive players in the AL. From 2005 through 2008, he averaged 22 homers, 29 stolen bases and 116 runs. He also won two Gold Gloves playing center field with reckless abandon, which led to the wear and tear on his body.
"I can't imagine playing any different," Sizemore said. "Everything is progressing well but one reason we are taking it slow is because I may have rushed things a year ago and that caused setbacks. When I return, I'll have to play it smart."
Last fall, the Indians declined to pick up a $9 million option on Sizemore, then re-signed him in November for one year at $5 million.
"I don't want to be with any other organization," Sizemore said, adding that he enjoys watching the first-place Indians, but would prefer to be in the lineup helping them.
"It definitely pushes you to want to get back," he said. "I want to be part of it."
Manager Manny Acta said he is cheered by Sizemore's progress, cautioning that he won't write his name on a lineup card until trainers are confident the outfielder is fully recovered.
"It's encouraging that we are playing good baseball without him, allowing him to just rehab and get healthy," Acta said. "Hopefully he can come in and give us a lift."