Chelsea believe that defender Ben Chilwell may have suffered an anterior cruciate ligament injury in their Champions League win over Juventus on Tuesday night.
The England left-back is currently waiting for the results of a scan that will reveal the extent of the damage.
The 24-year-old, who managed to walk gingerly off the pitch, was understood to be feeling less pain later on and Chelsea boss Thomas Tuchel will hope that means good news.
If not, it will be a hammer blow to both club and country, with Chilwell turning in a number of impressive performances in recent weeks.
He had regained his Chelsea place over Marcos Alonso and had contributed not only to his side’s excellent defensive record but also at the other end, with three goals and an assist in just six matches.
World Cup place in doubt?
The typical timeline to recover from an ACL injury is between six to nine months, meaning that in the best-case scenario Chilwell would be back over the summer, giving him a few months to push for a place in the England squad ahead of the World Cup.
The worst case would mean his place at that tournament would be in serious doubt.