Palmer didn't practice Wednesday due to a concussion.
Palmer played 61 offensive snaps and logged five catches on eight targets for 47 yards in this past Saturday's 24-22 loss to the Bills, but he was placed in the NFL's concussion protocol at some point after the game, according to Jeff Miller of the Los Angeles Times. The Chargers were also without Keenan Allen (heel) at Wednesday's practice, so for the time being, Quentin Johnston, Alex Erickson and Jalen Guyton are the Chargers' top healthy receivers as Sunday's game in Denver approaches.