Manchester United have confirmed that Rio Ferdinand is suffering from flu, casting doubt over whether the defender will play against Real Madrid on Tuesday.

The illness prevented Ferdinand from being named in the squad against Norwich City in the Premier League on Saturday afternoon.

Ferdinand was praised for his display in the 1-1 draw with Madrid in the first leg of the Champions League round-of-16 meeting in the Spanish capital but could now miss the return leg at Old Trafford.

No further statement has been released by the club as to whether it could affect his participation against the La Liga champions.