Guus Hiddink is fearful that bad news awaits when the full extent of the injury defender Kurt Zouma sustained in the 1-1 draw with Manchester United is revealed.
The French international landed awkwardly during the second half of the clash with the Red Devils and was visibly distressed as he lay prone on the Stamford Bridge pitch.
Zouma was taken away on a stretcher and Hiddink expects to have more news on Monday following tests.
The Blues boss feels it is likely the prognosis will not be good.
“We will know more [on Monday],” Hiddink said of Zouma’s injury.
“But if you have this injury then it’s bad. Let’s see. It’s a hyper extension and that’s always bad. I had the same problem once and it hurts a lot. We will see.”
Zouma was given his first international cap for France by coach Didier Deschamps last March in the friendly win over Denmark in Saint-Etienne as Les Blues continued their preparations for Euro 2016 on home soil this summer.
The 21-year-old has become a much more prominent figure at Chelsea this season, displacing Gary Cahill from his post at centre-back and will have high hopes of being in Deschamps’ squad come June.
Hosts France face Romania, Switzerland and Albania in Group A at the Euro 2016 extravaganza.
Chelsea needed a stoppage time goal from Spanish international Diego Costa to salvage a point against Man United but Hiddink felt a share of the spoils was merited for his team.
“They [United] made a beautiful goal without good marking from our side but it was a beautiful goal. Afterwards the team reacted very well and deserved this point,” he added.
France are 3.75 to win Euro 2016 this summer while reigning champions Spain are 6.00 to win outright.