Chelsea manager Carlo Ancelotti has admitted Ashley Cole's World Cup place is threatened by the fractured ankle which will keep him out of action for around three months.
Cole, 29, is expected to be sidelined until the closing weeks of the Premier League season after picking up the injury during Wednesday's 2-1 defeat at Everton.
He now faces a race against time to be fit for the World Cup Finals and England's first fixture against the USA in Rustenburg on June 12.
Asked whether Cole would be fit for the tournament, Ancelotti told Sky Sports News:"I don't know. I think so. I hope for him and for the England team.
"We are very disappointed because Ashley is a very important player for us.
"Now we have to do our best to help him recover quickly."
Cole's injury opens the door for Wayne Bridge to stake a claim for a World Cup place before the tournament begins.
The Manchester City defender has found himself in the spotlight in recent days after his former partner was revealed to have been involved in a relationship with ex-Chelsea team-mate John Terry.
Terry was stripped of the England captaincy by England coach Fabio Capello last week amid suggestions that his relationship with Bridge had broken down.
However, Bridge could now feature in the friendly international against Egypt at Wembley on March 3.