actually JT plays in goal a lot during training. He enjoys it apparantly and Cech and Cudicini have been coaching him for the last couple of seasons during training sessions in case a situation like this occurs. Chelsea tried a few outfield players for the task but JT was the most enthusiastic and also the more gifted of the outfield players as a goalkeeper.
Oh yeah, I remember that Joga Bonito video of Rooney playing as goalie. I think that it's probably on Youtube, everything is on Youtube these days.
Glen Johnson subbed in as goalie a couple of seasons ago when Cudicini I think got a red in the FA Cup loss to Jongleurs FC and all 3 subs had been used. We lost 1-0 and finished the game with I think 7 men because of injuries, etc.