Both sides are missing critical players as a result of injury; Stanton in for Carson Palmer and perhaps more crucially for our purposes, NaVorro Bowman is out, weakening an already suspect San Francisco LB corps.
It's not worth getting heavily involved, but the Cardinals should be able to dominate on the ground on offense to cover and hold the 49ers running game in check.
Pick: Cardinals -3.5 @ 1.91