He's played well enough that the door for him is still open and there will likely be packages for him week to week. Short yardage situations he can put the defense into a real bind.
But he still left plays on the table. Can throw to the open guy, but can he throw a guy open? Steelers probably couldn't have had this timed better with their bye in two weeks. Do your due diligence and kick the tires on Russ. If not you come back after the bye with a renewed focus on Fields.