John Terry has been forced out of a Chelsea training session after suffering an ankle injury.
The England and Blues captain was already a doubt for the club's Premier League clash against Tottenham Hotspur on Thursday following a knee problem sustained during Chelsea's 1-1 draw with Wigan Athletic.
The London side confirmed on their official Twitter feed that the 30-year-old is being treated by medical staff after picking up the injury in the opening training session.
Andre Villas-Boas's side are currently fourth in the league table, nine points adrift of leaders Manchester City.