Mitchell (knee) has been ruled out for Sunday's game against Arizona, Nick Wagoner of ESPN.com reports.

EDGE Analysis

Jordan Mason will replace Mitchell as Christian McCaffrey's backup for a second straight game. It's a role that comes with minimal playing time apart from blowout situations, though Mason did score a three-yard TD against the Seahawks last week after McCaffrey ripped off a 72-yard run on the first play from scrimmage and needed a breather. Mason played just five snaps thereafter and finished with five touches for 26 yards and the touchdown.