One of the NFL's best defensive players has decided to call it quits, with Troy Polamalu announcing his retirement after 12 seasons on Thursday. The safety, who played his entire career with the Pittsburgh Steelers, should be a lock for induction into the Pro Football Hall of Fame.

Polamalu, 33, was named to the Pro Bowl eight times. He’s a five-time All-Pro and a two-time Super Bowl champion. Polamalu played at his highest level in the 2010 season when Pittsburgh lost to the Green Bay Packers in his third Super Bowl appearance, and also won the Defensive Player of the Year award.

There were few players that had as much of a defensive impact as Polamalu did during the course of his career. In his final season, and perhaps due to nagging injuries, Polamalu was no longer the defensive force that he had once been. But his entire body of work makes him one of the best safeties the NFL has ever seen. The Southern California native finished his career with 771 combined tackles over 158 games.

During his prime, opposing offenses always had to account for where Polamalu was on the field. Constantly in motion before the snap, No.43 seemed to always put himself in position to make either an interception or sack the quarterback.

More than anything, Polamalu was a playmaker on the defensive end. In both 2008 and 2010, his seven interceptions ranked second in the league, and he set a career-high in 2013 with five forced fumbles. The former USC star had just 12 career sacks, but a few were highlight-reel plays, leaping over the line of scrimmage and getting to the quarterback after the ball had barely been snapped. He was also able to time the snap count and stop running backs a few yards behind the line of scrimmage.

Offensive players are usually the NFL’s most popular, but Polamalu was so exciting to watch that his position didn’t matter. His style of play, winning attitude, and even his trademark lengthy, curly hair made him a fan favorite. He had the No.1 selling jersey in 2010, and he was consistently in the top three.

Polamalu may not be guaranteed a spot in the Hall of Fame when he first becomes eligible. He was arguably the best player at his position for multiple years, but Polamalu played a position that isn’t well represented in Canton. Only 24 total defensive backs have been elected to the Hall of Fame, and less than half played safety.

Aeneas Williams retired in 2004 and he was the last defensive back to play safety and become a Hall of Famer, though he was predominantly a cornerback. Hall of Famer Rod Woodson was a versatile cornerback, and he retired in 2003. Hall of Famer Ken Houston ended his NFL career 35 years ago, and no player that strictly played safety since has a bust in Canton.