I think I tell the whole team to meet at the stadium the following day. Sunday is usually a rest and recover day, so being forced to come to the stadium won't sit well with a lot of the team. Then I tell the player... "we've gone over this, but you still put yourself above the team, so now the entire team is going to watch you run the stairs. Every stair. And if you don't finish within X minutes, then the entire team is going to run the stairs."

The number of minutes will depend on the player's body type. It will be something that he should be able to finish easily, but if he slacks off too much he'll be in danger of not finishing.