If they give him a fair shot he will play lights out.
IMO this is the issue. He's not going to get a fair shot this week. Mitchell went down and Wilson ended up on the field for 40 plays, Mitchell was in for 17, the Niners ran 68 plays total. Mason got 0 snaps on offense.
I know everyone thinks Shanahan plays games with his RBs, but that's mostly perception not reality. Shanahan is one of the very few HCs who reliably feeds his lead back until the wheels fall off and then it's next man up.
Wilson is the lead back this week. He's going to eat all the

. If he goes down we'll see who Shanahan likes more among whoever is active this week.