Chelsea's injury crisis has deepened after the club confirmed defender Ricardo Carvalho is expected to be out of action for at least a month.

But the centre-half could be out for longer, possibly the rest of the season, if he requires corrective surgery on the ankle ligament injury he sustained in the first-half of Wednesday night's 5-0 victory over Portsmouth.

Chelsea defender Branislav Ivanovic will be out for a month after injuring his knee in Sunday's 1-1 draw against Blackburn Rovers, meaning another game in the Chelsea Hospitality seats.

The 26-year-old has torn his medial knee ligament and was replaced by Yuri Zhirkov during the game at Ewood Park.

The injury to the Serb will be a blow to Carlo Ancelotti's Premier League title contenders, who are four points behind leaders Manchester United.