Troy Polamalu said he changed up his offseason rehab and training routine this year to try to ensure that his bothersome calf won't keep him off the field in 2013.

The Pittsburgh Steelers' star safety missed missed more than half of last season with a calf injury. He said, for the first time in his career, he felt this injury was one that didn't have to happen.

"There are times when people fall on my knee, and those type of freak accidents that can't be avoided. Last year was the first injury of my career that could've been avoided," he told reporters.

The 2010 NFL Defensive Player of the Year declined to get into specifics on how he could have kept the calf healthy but says his offseason regimen continues to change as he matures.

"Time is not stale," Polamalu, 32, said. "You have to continue to evolve as time evolves, your career evolves and your body evolves. I think when you become stale in that way, then it's just kind of a redundant thing."

Polamalu's calf has bothered him since 2009 but last season was the first time it kept him off the field for a significant amount of time. He said his goal this offseason was to break up the scar tissue that has built up in his calf over the years. He said he "found a great physical therapist" to assist him in that area.

"If you don't attack the problem of scar tissue, then you're just going to continue to have problems," he told reporters, adding that he hopes to "make these problems obsolete."