He would then be forced off after a bad landing following a tussle with Rafael Leao and tried as he did to run it off, he had to be replaced by Trevoh Chalobah and left Stamford Bridge on crutches.
Chelsea manager Graham Potter confirmed the blow after his side’s first in the Champions League: “That is the only disappointing thing about the night.
“We need to scan tomorrow and fingers crossed, I would not want to speculate on anything at the movement.
“But we are concerned but we just have to wait until tomorrow and get it scanned and hope for the best.”
The French under-21 star joined Chelsea on a seven year deal with £ 70 millions and he was just beginning to find his rhythm and consistency after playing a key role in both the league win at Crystal Palace and now AC Milan before injury struck.
Chelsea were already without the influential N’Golo Kante who has not kicked a ball since the Premier League game against Tottenham even though he’s been back training on the grass.
In some positive news the 3-0 win against AC Milan was the first time Chelsea had kept a clean sheet since the opening day of the season against Everton and this will encourage them.
They will now hope that they get three wins on the bounce when they face managerless Wolves in the Premier League this weekend.