Pittsburgh Steelers safety Troy Polamalu has retired, the team announced Friday.

Polamalu played 12 seasons for the Steelers (2003-2014). He is an eight-time Pro Bowler (2004-08, 2010-11, '13), and has been named first-team AP All Pro four times (2005, 2008, 2010-11) and second team two times (2004, 2007).

New Orleans Saints cornerback Keenan Lewis played his first four years in the NFL with the Steelers and Polamalu. Lewis posted a message on his Instagram account (@BallLike28) Friday morning dedicated to his former teammate:

"The game will miss one of the best safeties to ever play the game," Lewis posted. "This is a guy who took me under his wing since Day 1. He taught me how to be a man, a professional and a teammate. Congratulations Troy Polamalu on a stellar career. When he goes to Canton, Ohio to give that speech, I will be there. Love you 43."

Saints safety Jairus Byrd tweeted this about Polamalu: "God bless @tpolamalu on the next phase of life. He redefined the safety position. Truly one of the greatest players on and off the field."