Chelsea defender Wesley Fofana has suffered another serious injury ahead of the new season.
Fofana, who was a big money signing from Leicester City last summer, has been blighted by issues since arriving at Stamford Bridge.
The France international will now miss a significant chunk of the season with an anterior cruciate ligament injury.
Chelsea posted a statement on the club's website which read: "Defender Wesley Fofana has undergone anterior cruciate ligament reconstruction surgery.
"The 22-year-old did not travel to America for the club's pre-season tour due to specialist medical assessments, which unfortunately confirmed that an operation would be required.
"Wesley will now begin his recovery and work with the club's medical department at Cobham during his rehabilitation phase."