German captain Michael Ballack has stunned Chelsea by revealing he could retire from football after next year's World Cup - on the day the club was hit with a transfer ban until 2011.
Ballack's £120,000-a-week contract expires next summer and the Blues have failed to open talks with the midfielder on a new deal.
But Chelsea will not want to lose the midfieder now after being banned by FIFA for signing any new players in the next two transfer windows.
The club was found guilty of inducing Gael Kakuta to break his contract with Lens in 2007.
However Ballack, who will be 34 by the time the ban is lifted, insists he will not make a decision on his future until after South Africa in 2010.
The German, who scored against Burnley in Chelsea's 3-0 win at Stamford Bridge last Saturday said: 'I will decide after the 2010 World Cup if I will continue playing or if I will stop. I will continue as long as I enjoy it and still have ambitions in the sport.'