Chelsea are threatening to take action against any season ticket holder or member found to be involved with death threats reportedly made towards last night's Champions League referee. Tom Henning Ovrebo turned down a number of good penalty shouts for the home side, and was angrily confronted by Blues players after the defeat to Barcelona. A statement on the club's website says they've contacted the police and they've not received any complaints. Staying with the fall-out from Chelsea's defeat - UEFA will be considering disciplinary action against the club. It's the reaction of Didier Drogba and Michael Ballack in particular that will be the focus - the pair acted aggressively towards the referee at the final whistle.