Miller is expected to get some work tonight with Nall, as both try to fill in for Montgomery who is out with a concussion. Miller's workload likely isn't safe, but it could depend on how he produces with any touches early on in the game. Miller hasn't played since tearing his ACL last year before the 2019 season.
CHI RB Ryan Nall - Week 10 Fantasy Football Outlook
Week 10 vs. Minnesota Vikings
UPDATE: David Montgomery has been ruled out, which leaves Ryan Nall and Artavis Pierce as the remaining running backs. Cordarrelle Patterson will also likely see some backfield touches. The Bears could also call up Lamar Miller from the practice squad. In short, there are a lot of options to replace Montgomery and none of them are great. Patterson offers the most upside, but he may only have WR designation in your fantasy league, which doesn't help when replacing a running back.
Ryan Nall surprisingly went 4-35-1 as a receiver out of the backfield last week as he saw increased playing time with David Montgomery's injury. If Montgomery is active this week then Nall is irrelevant. if Montgomery is inactive, then Nall would carry some value, but not much. We'd have to wait and see if the Bears bring up Lamar Miller from the practice squad. If so, then Nall would not be a strong play in fantasy.