Head coach Bruce Arians said that Palmer will not travel with the Cardinals to Santa Clara. The quarterback had made progress this week while in the concussion protocol, but the team does not want to take any chances. Palmer did not practice this week.
Stanton, 32, was the quarterback in 2014 when the Cardinals beat the 49ers 23-14. He passed for 244 yards and two touchdowns in the September matchup.
Stanton is 7-5 as a starter, but has completed just 54-percent of his passes and thrown 18 interceptions compared to 12 touchdowns.