SANTA CLARA -- Tight end Vernon Davis, who continues to go through the NFL-mandated protocol in order to gain clearance to return from a concussion, is not expected to practice Wednesday, 49ers coach Jim Harbaugh said.
Davis sustained a concussion in the first quarter of the 49ers' 42-13 loss Sunday night when Seattle Seahawks safety Kam Chanceller hit him high while breaking up a pass. Chancellor was penalized for unnecessary roughness.
Davis must first receive clearance from an independent neurologist before he can return to practice. Harbaugh said Davis has not experienced a setback. Davis appeared on the practice field Wednesday and took part in individual stretching.
Meanwhile, the 49ers figure to promote receiver Ricardo Lockette or Chad Hall from the practice squad to fill the vacancy left by Mario Manningham's season-ending knee injury. Harbaugh suggested the 49ers could also fill the final roster spot with a practice squad player at another position.
The 49ers have no intention of looking outside the organization to a veteran player to fill the roster spot, Harbaugh said.
Harbaugh suggested that there will be competition among the wide receivers in practices this week to determine which player suits Sunday, along with Michael Crabtree, Randy Moss and Ted Ginn, the punt-return specialist.
"A.J. (Jenkins) will step up," Harbaugh said of the 49ers' first-round draft pick. "We'll look at a couple of other options at receiver, but that group will have to step up."
Defensive tackle Justin Smith, who missed the 49ers' past six quarters of action, continues to rehab his left arm/elbow, Harbaugh said. His availability for Sunday's season finale against the Arizona Cardinals remains in question.