Manchester United’s 2-0 defeat at Liverpool has again exposed the chinks in the Premier League champions’ armour, notably their defensive frailties against top level opposition.

While United overcame Rio Ferdinand’s howler in a 4-3 win over City in the Manchester derby, the England centre back’s lack of pace and cutting edge cost Alex Ferguson’s side dearly against Liverpool.

The ease with which a half-fit Fernando Torres got away from Ferdinand to score Liverpool’s opening goal will have raised not only Ferguson’s eyebrows, but also given Fabio Capello a headache.

Is Ferdinand, who has looked completely at sea in the heart of United’s defence this season and had a nightmare of a game in England’s 1-0 defeat by Ukraine, going through just a temporary loss of form or are his best days behind him?

Ferguson has no world class cover for Ferdinand in his squad and his decision to let Gerard Pique return to Barcelona after United’s 2008 Champions League triumph might come back to haunt him. That is if it hasn’t already…Pique stopped United from taking the lead in the 2009 final while Ferdinand was at fault for Barcelona’s second goal in the 2-0 defeat by the Spanish champions.

England’s potential rivals in the 2010 World Cup will also be rubbing their hands over Ferdinand becoming a liability and while Capello must hope he rediscovers his form, the Italian might also want to consider an alternative partner to John Terry in the centre of England’s defence.

PHOTO: Liverpool’s Fernando Torres (front) outmuscles Manchester United’s Rio Ferdinand to score during their English Premier League match at Anfield, Oct 25, 2009. REUTERS/Phil Noble