Manchester United manager Louis van Gaal faces the toughest test of his reign so far on Sunday when Chelsea visit Old Trafford
Chelsea live updates
Diego Costa is among a number of injury concerns as Premier League leaders Chelsea travel to Crystal Palace.
Costa, who has been troubled by a hamstring problem in recent weeks has an undisclosed problem, while Ramires (groin) and Didier Drogba (ankle) are also doubtful.
Andre Schurrle (illness) and John Obi Mikel (undisclosed) are also to be assessed prior to the Selhurst Park clash.
Provisional Chelsea squad: Courtois, Cech, Ivanovic, Luis, Fabregas, Zouma, Ake, Ramires, Oscar, Hazard, Drogba, Mikel, Schurrle, Salah, Remy, Costa, Matic, Willian, Cahill, Terry, Azpilicueta, Christensen, Boga, Baker, Schwarzer.
William Gallas has retired from football at the age of 37.
The former France defender, who took in the likes of Arsenal, Chelsea and Tottenham during his career, has told French TV he has decided to call it a day.
Gallas will on Thursday night give a full interview to Sport Confidential about his decision, but in a quote carried by L'Equipe he said: "It is something that is not easy to announce.
"You think that you can continue, but today I cannot."
Full time, #CFCU18 12-2 Aston Villa. The youth team come from behind to win an incredible game!
Belgium midfielder Eden Hazard will not feature in tonight's Euro 2016 qualifier against Andorra due to a toe injury, national coach Marc Wilmots has confirmed.
The 23-year-old joined up with his countrymen despite picking up the knock during Chelsea's 2-0 Barclays Premier League win over Arsenal on Sunday, but will not be risked in Brussels with one eye on Monday's clash with Bosnia-Herzegovina in Zenica.
Wilmots tweeted, in French and Dutch: "As a precaution, @hazardeden10 will not play against Andorra because of a bruised toe. Trying to get him 100% for #bosbel."
Wilmots also revealed on Twitter on Thursday evening that Hazard's club and international team-mate Thibaut Courtois was feeling no ill-effects from the head injury which ended his weekend involvement against the Gunners.
"@thibautcourtois has trained from the beginning to the end without any problems," he posted.