Safety Troy Polamalu practiced with the first-team defense Friday at the start of the Steelers' mandatory minicamp. Polamalu missed 11 games last season with a left knee injury that he confirmed did not require offseason surgery.
"We had a couple of OTA practices last week and it feels good," Polamalu said of his knee. "It's feeling better with time, thank god."
Polamalu says strong offseason training and rehab has him back on the right track, but "it's still a process." He had some limited practice reps with the team during the end of last season but hasn't played in a game situation since Nov. 15 during Pittsburgh's loss to the Cincinnati Bengals.
"It's just timing, rhythm and getting the right read and reaction with the eyes and coordinating with the body," Polamalu said of returning. "I think it would probably be easier to lose if the defense were to change quite a bit. But when you feel comfortable within the system, it still takes time, but it wouldn't take me as much time."
With Roethlisberger facing a conditional six-game suspension, Pittsburgh's defense will have to be the strength of the team early next season. The unit struggled late in games in 2009 without Polamalu in the lineup, as the Steelers failed to make the playoffs with a 9-7 record.
James Walker covers the AFC North for ESPN.com.