The 25-year-old pulled up in the dying moments of Chelsea’s 2-1 Champions League win over Dinamo Zagreb on Wednesday night.
After leaving Stamford Bridge on crutches with the aid of medical staff, the initial assessments on Chilwell have not been positive and have put his estimated recovery time at between four and 12 weeks.
Chelsea suspect that he has suffered a grade two hamstring tendon tear which will see him miss the World Cup in Qatar.
Graham Potter has been told not to expect him to play in the final three matches before the showpiece event against Arsenal, Manchester City and Newcastle.
The injury represents a huge blow for Chilwell, who spoke of his dream of lining up at a World Cup with the Three Lions over the summer.
It also represents another injury lay-off after he got injured on Christmas Day last year, forcing him to have major anterior cruciate ligament surgery on his knee.
Manchester United's Luke Shaw will start on the left side of England's defence at the upcoming World Cup and Gareth Southgate must look around for back-up options in Chilwell's absence.
Tottenham's Ryan Sessegnon, Leicester's James Justin or Crystal Palace's Tyrick Mitchell could get the call with Southampton's Kyle Walker-Peters also out with a hamstring issue.