High flying Chelsea will be without midfielders Emmanuel Petit and Juan Sebastian Veron when they visit Elland Road on Saturday.
Also, striker Eidur Gudjohnsen and defender Celestine Babayaro are doubtful.
Nigerian Babayaro, who played against Reading in the Carling Cup last night, had his right knee wrapped in ice at the training ground near Heathrow Airport.
England international Wayne Bridge is likely to take his place at left back.
Icelander Gudjohnsen injured his ankle during a training session last week, club sources said.
Veron returned from international duty with Argentina last month with a neck problem and Petit is recovering from knee surgery.
Jimmy Floyd Hasselbaink is likely to start against his old club, whom he has never scored against since leaving, and he could be partnered up front by Romanian international Adrian Mutu.
Mark Viduka will be making his 150th appearance in the English and Scottish Leagues.