The center fielder returned for 10 games last September after missing half of July and all of August. Sizemore then headed back to the disabled list, where he has remained through the first two months of this season.
"I tried [rushing back] last year, and it didn't help me at all," Sizemore said. "I ended up just putting myself in a worse position. What I've gone through is why we're taking it slow now. It's important to not just feel good, but feel really good, great."
Indians manager Manny Acta said Monday that Sizemore is still not close to a rehab assignment. Sizemore has yet to run the bases, and there's currently no timetable for his return.
"Anything could be realistic," Sizemore said. "I couldn't even tell you what I'll be doing next week. ... It just depends on how I feel. I feel good, but it's still in a controlled environment. For me, the test will be how I feel when I'm out there playing, where I just have to react. When I know which way I'm going, it's a lot easier."
While it's sometimes hard for him, Sizemore said he still watches many of Cleveland's games. He's pleased with the way the team has started the season without him, especially his replacement in center -- Michael Brantley.
Sizemore was watching when Brantley robbed Chicago's Alex Rios of a home run on Saturday.
"It was pretty impressive," Sizemore said. "Those are things I used to be able to do."