Still, the defending AFC champions didn't want to take any chances, signing the star safety to a contract extension through the 2014 season. The deal is worth $36.5 million with $10.55 million guaranteed, a league source told ESPN NFL Insider Adam Schefter.
Polamalu, the 2010 NFL Defensive Player of the Year, actually signed the contract at Pittsburgh International Airport on Saturday just before the team boarded a plane to Baltimore.
The 30-year-old took to his Twitter account to announce the deal, tweeting "I am happy to say that I will retire a Pittsburgh Steeler!"
The perennial Pro Bowler enjoyed perhaps the finest season of his career in 2010, finishing with seven interceptions, 64 combined tackles and a sack. He was slowed by a strained Achilles in the playoffs and has admitted he was not 100 percent in the loss to Green Bay in the Super Bowl.
Polamalu was ready to start the final year of a five-year deal he signed in 2007. The Steelers typically do not negotiate contracts once the season begins. They got it in just under the wire, saving both sides from a potential distraction over the next five months.
The contract is the third extension the Steelers have handed out to defensive starters since training camp opened. Linebackers Lawrence Timmons and LaMarr Woodley both agreed to long-term deals last month and Polamalu's signing gives the Steelers stability well into the future. Pittsburgh returns all 11 defensive starters from a unit that led the league in points against a year ago.
Polamalu paced himself during camp, though he showed flashes of brilliance in a preseason win over Philadelphia three weeks ago, intercepting Michael Vick and going on a freewheeling return that included a fake pitch and an abrupt ending after Vick drilled Polamalu in the knees.
Cornerback Ike Taylor has been so impressed during camp he felt the need to declare "Troy's back." Actually, Taylor said, he never went anywhere in the first place.
"Sure, he missed a couple games," Taylor said, "but the games he was in there, he had like seven picks in six games.
"So, Troy is Troy."
If the negotiations were weighing on Polamalu, it didn't show. He declined to comment on the need to get a deal done earlier in the week, saying he'd prefer to keep all discussions between his agent Marvin Demoff and the team quiet so that things don't get "misconstrued."
Still, his intention was to remain in Pittsburgh, where he has become one of the best players in the league quarterbacking defensive coordinator Dick LeBeau's 3-4 attack.
Polamalu's frenetic play, along with his soft-spoken personality and flowing black locks have made him a fan favorite. His No. 43 jersey is among the top sellers in the NFL, ahead of teammates like quarterback Ben Roethlisberger and linebacker James Harrison.
The signing means the Steelers have only one impact player -- wide receiver Mike Wallace -- not locked up beyond the 2011 season, though Wallace would only be a restricted free agent at the end of the season and Wallace, like Polamalu, has professed his desire to remain with the team.
Information from The Associated Press contributed to this report.