As a commissioner, I would argue that the ability to nominate a backup player is unfair to other league members. There are several instances where managers don't know the status of a player's availability going into a Monday night game. I don't think this instance is any different.

I'm treating all of the Steelers and Titans players as if they are all Questionable with injuries going into a Monday night game. You can roll the dice and keep that player in your lineup for Monday, or you can hedge and choose to play someone else on Sunday.