Oakland Raiders quarterback Carson Palmer left Sunday's game against the Carolina Panthers after taking a shot to his back from defensive end Greg Hardy in the first quarter and was ruled out for the remainder of the contest.
Matt Leinart replaced Palmer, who suffered a rib injury, as the Raiders' quarterback.
Palmer was flushed out of the pocket, rolled to the right and stopped to set up. That's when Hardy came barreling in from behind and hit Palmer in his lower back with the crown of his helmet. Officials flagged Hardy for unnecessary roughness because he led with his helmet, resulting in a 15-yard penalty and an automatic first down.
Palmer finished 3-of-3 passing for 31 yards.
The Raiders also announced defensive back Phillip Adams (groin) and safety Tyvon Branch (foot) are out for the remainder of the game as well.
The Associated Press contributed to this report.