Click to enlarge, and debate the strip below the line.

Keith Hackett's verdict

1) Stop the game, and, first things first, make sure the keeper isn't injured. You have to treat this as though the ball has made contact with an outside agent. So restart the game with a dropped ball at the nearest point on the six yard goal area line, parallel to the goal line. You should also recheck the state of the goalposts, to make sure they do not pose a danger to the players.
Daniel Hamilton wins the shirt.
2) Award the goal, then show the defender a yellow card for unsporting behaviour. You played advantage as the other attacker had an obvious goalscoring opportunity, so you cannot dismiss him for denying an obvious goal scoring opportunity. Thanks to Dr Laurie Judd.
3) Obviously, this should have been sorted before kick-off, but as he has sprung it on you, you have to think on your feet. Bear in mind that you have no authority to prevent a player from playing for legal reasons, but you can, before kick-off, allow either or both teams to replace the players concerned. So consult with the management of both teams and advise them of the problem. If the clubs refuse to withdraw the players, then you have to go ahead with the game, keep a careful eye on the pair, and advise all concerned that the authorities will deal with it after the game. Thanks to John Willoughby.

Competition: win a T-shirt of your choice

For a chance to win a Philosophy Football T-shirt of your choice from the Guardian sport range send us your questions for You are the Ref to you.are.the.ref@observer.co.uk. The best scenario used in each new strip wins a T-shirt; Terms apply. For more on You are the Ref's history, click here.