Strong safety Troy Polamalu made one of the plays of the game Sunday for the Steelers, then left for good because of concussion-like symptoms.
Polamalu injured himself while taking out the legs of Jacksonville running back Maurice Jones-Drew on third-and-1 with 9 minutes, 36 seconds left in the game.
The injury is not believed to be serious, and coach Mike Tomlin said after the 17-13 win that the Steelers held out Polamalu because they "wanted to err on the side of caution."
Polamalu, who stopped Jones-Drew short of a first down, did not address the media after the game.
In other injury news, starting left guard Doug Legursky left at the beginning of the second quarter with a dislocated toe on his left foot. He did not return. Nose tackle Chris Hoke left later in the quarter after sustaining a stinger and also did not return.
Hoke said he hopes to play Sunday when the Steelers visit the Arizona Cardinals.
"I've just got to take it day by day," he said.