Reds wait on Rio rib injury

United could be without Rio Ferdinand for the decisive second leg against Arsenal after the influential defender headed to hospital on Wednesday night.

The centre-half left the field a few minutes before the end of the European champions' 1-0 victory, having taken a blow to his torso as the Gunners pressed unsuccessfully for an equaliser.

Ferdinand sustained the injury in a ruck of players when Arsenal substitute Nicklas Bendtner headed over from a Cesc Fabregas free-kick, the nearest the visitors came to breaching the Reds' rock-solid back line.

"Rio got a crack right on the ribs and we hope there’s nothing broken," said Sir Alex Ferguson.

"If you get a rib injury, you could be out for two to three weeks maybe. We just have to wait for the (hospital) results obviously."

Jonny Evans came on for Rio to help the Reds complete a priceless clean sheet and the young Irishman is now set to deputise for at least Saturday's league game at Middlesbrough.