Vidic blow leaves Manchester United with defensive shortfall

(CNN) -- Manchester United were dealt a serious blow Tuesday as captain and key central defender Nemanja Vidic was ruled out for at least two months with a knee problem.

The Serbian star missed the final five months of last season after rupturing his cruciate ligament and a fresh problem has emerged on the same knee.

"Nemanja Vidic has had a meniscus operation on his right knee and will be out for around eight weeks," read a statement on the club's official website.

The new injury setback for the 31-year-old could not have come at a more unfavorable time for the English Premier League giants, who are also missing a number of key defenders ahead of vital league and Champions League clashes.

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England internationals Phil Jones and Chris Smalling are currently sidelined, the former with the same problem as Vidic, leaving manager Alex Ferguson with only two fit regular central defenders.

That includes Jonny Evans, who picked up a minor injury in the 2-1 victory over Liverpool at Anfield Sunday which left United in second place in the early standings.

United's neighbors and EPL champions Manchester City suffered a shock 4-2 home defeat Tuesday to Aston Villa in the English League Cup.

City were twice ahead through Mario Balotelli and Aleksandar Kolarov, but two goals from Gabriel Agbonlahor, allied to an own goal from Gareth Barry and an extra time strike from Charles N'Zogbia saw Villa into the fourth round.

Meanwhile, league leaders Chelsea continued their fine start to the domestic campaign with a thumping 6-0 home win over second-flight Wolves.

John Terry, who quit the England captaincy just ahead of his FA hearing into charges that he made a racial slur in an EPL match last season, lined up for the match at Stamford Bridge.

Gary Cahill put Chelsea ahead after just four minutes and it was one-way traffic throughout with Fernando Torres scoring in the second half and new Victor Moses rounding off the scoring.

In an all-EPL clash, Wigan won 4-1 at West Ham after the home side had taken an early lead while high flying Everton were shocked 2-1 at Leeds to make a surprise exit.