Chelsea hope either Diego Costa or Loic Remy will be fit for Sunday's match at Arsenal after Didier Drogba suffered an ankle injury.
Drogba, 37, has led the Premier League leaders' attack in wins over Queens Park Rangers and Manchester United in recent weeks due to Costa's hamstring injury and Remy's calf problem.
The former Ivory Coast striker, also a United Nations Development Programme Goodwill Ambassador, withdrew on Monday from featuring in the Match Against Poverty in St Etienne.
He wrote on Twitter: "Disappointed not to be able to play the #MAP2015 because of an ankle injury but still supporting #EbolaResponse."
It is not the first time Drogba has had an ankle problem this season.
He has made five Premier League starts this campaign, but could be displaced in Chelsea's starting XI at the Emirates Stadium anyway if either Costa or Remy are fit.
"Our target was for Diego to play the last four matches and Arsenal is the sixth match from the end," Jose Mourinho said last Friday. "He starts training with rest of the squad next week."
Mourinho also reported Remy had a better than 50 percent chance of playing against United, although teenager Dominic Solanke was on the substitutes' bench with the France striker ruled out.
Chelsea are 10 points clear of the second-placed Gunners, and victory against Arsene Wenger's men will mean the Blues can wrap up the title at Leicester three days later.
Drogba said last week that he has no plans to retire this summer, telling the Evening Standard: "[This year] isn't going to be my last season."