Chelsea captain Reece James has suffered another setback after injuring a hamstring in training, Blues manager Enzo Maresca has revealed.
The 24-year-old missed much of last season after undergoing hamstring surgery, which was designed to help him overcome a series of injuries, but returned to action last month.
Maresca played down concerns about a long-term lay-off but confirmed James will miss Saturday's match at Leicester.
He said: "We have just one injured player and that's Reece [James] who unfortunately felt something small in training two days ago and we don't want to take a risk for the weekend.
"It's a hamstring, muscular problem. We will see, we don't know for how long, for sure [we want him fit for longer]. At the moment it is not happening but we hope it will happen soon.
"He is out this weekend but hopefully he can be back soon. It's probably difficult that he can be available for the Conference League [next Thursday], but hopefully soon."
The likes of Cole Palmer, Levi Colwill, Wesley Fofana, Malo Gusto and Romeo Lavia are all available despite pulling out of international duty last week.
But there is caution around Moises Caicedo and Enzo Fernandez with Maresca saying his starting team will "not be at 100%", with those travelling from international duty in South America completing just one training session on Friday before the match.