Manchester United manager Sir Alex Ferguson is facing a major defensive headache ahead of Tuesday's Champions League clash with Wolfsburg.

United ended Saturday's 4-0 Premier League win over West Ham with Michael Carrick and Patrice Evra at centre-back and Ryan Giggs at full-back after Gary Neville and Wes Brown added to an already-lengthy injury list.

Ferguson is now hoping Nemanja Vidic will recover from flu in time to partner Carrick, while Darren Fletcher is expected to continue at right-back.

"Evra must be the smallest centre half in the world," said the United boss. "But he's a good reader of the game. He's quick and determined.

"I don't know where I'm going to get a back four for Tuesday. Probably Nemanja Vidic will be back from flu and I'll probably play Carrick alongside him."