Team A ball on 50. Team A has already broken it's huddle with 10 players. Player A80 is not paying attention as Coach A's requests him to go on the field. The team lines up, Team A QB A12 notices A80 running on the field at the A47, parallel to the line of scrimmage.
Do we have anything different if A80 is still running (in motion and never stopped) and the ball is snapped while (a) has not made the numbers or (b) has made it past the numbers ?
In (a), I think I have a live-ball foul, illegal substitution, and possibly illegal participation.
In (b), I think I have a live-ball foul, illegal shift, as the substitute is now a 'player' after crossing the numbers, but he has not become motionless for one second before the snap.
Do we 'kill the play' and enforce a dead-ball, illegal substitution, in either case?