The Blues midfielder was forced off in the first half
Chelsea midfielder Mateo Kovacic had to be taken out of Wednesday's clash with Leeds after the Croatian was the victim of a horror tackle from Dan James.
Kovacic had to be replaced by Ruben Loftus-Cheek in the 30th minute with Chelsea leading 1-0 on a Mason Mount goal.
James was sent off for the foul, leaving relegation-threatened Leeds down a man and a goal within the opening half.