Palmer, who is currently subject to the league's concussion protocol, seems unlikely to play Thursday against the 49ers, NFL.com's Ian Rapoport reports.

EDGE Analysis

Palmer was knocked out during the fourth quarter of Sunday's loss to the Rams, resulting in backup Drew Stanton finishing the game at quarterback. With only a few days before the Cardinals' Week 5 contest, Palmer always faced a quick turnaround to play, but it seems doubtful he'll be able to do so now that he also has a concussion to overcome. Following this Thursday's game, Arizona doesn't play again until Oct. 17, essentially giving Palmer two weeks to be cleared if he indeed misses this week's NFC West tilt.