Mattison (concussion) was listed as a non-participant on Wednesday's practice estimate.
Mattison departed this past Sunday's win against the Saints with a head injury and eventually was confirmed to be in the concussion protocol Monday. With no on-field work to speak of to begin Week 11 prep, he doesn't appear to be in a great spot ahead of Sunday's game at Denver. If Mattison is unable to gain clearance from an independent neurologist by Saturday, the Vikings may be forced to use the combination of Ty Chandler, Kene Nwangwu and recent practice-squad signee Myles Gaskin out of their backfield this weekend.