Chelsea rocked by Ricardo Carvalho ankle injury

Carvalho will miss the key game against Man Utd at Old TraffordChelsea will be without Ricardo Carvalho for at least four weeks after the defender suffered ankle ligament damage in the 5-0 win over

Portsmouth.

Chelsea will decide over the next 24 hours whether Carvalho needs surgery.

If the 31-year-old is out for just four weeks he could return for Chelsea’s last three Premier League matches.

But he will miss key league games against Aston Villa and Manchester United as well as an FA Cup semi-final against Martin O’Neill’s side.

Carvalho’s injury leaves Chelsea with just two first-choice central defenders in Brazilian Alex and captain John Terry and comes just days after right-back Branislav Ivanovic was ruled out for a month after he picked up an injury in the 1-1 draw at Blackburn on Sunday.

Chelsea are also currently missing left-back Ashley Cole, midfielder Michael Essien and right-back Jose Bosingwa for much of the season.

Cole is recovering from a fractured ankle, Essien has a serious knee injury, while Bosingwa needs more surgery on his ankle problem.

Carvalho was injured in the first-half of the win over Portsmouth at Fratton Park, coming off in the 37th minute, with Alex replacing the Portuguese defender.

Meanwhile the Football Association will not punish Chelsea striker Daniel Sturridge over an incident involving Portsmouth’s Tommy Smith in Wednesday’s game.

Smith’s nose was broken after being caught by Sturridge’s elbow but the FA view it as “off-the-ball”, meaning referee Lee Mason was deemed to have dealt with it at the time.