Chelsea defender Wesley Fofana has been forced to undergo surgery on an ACL injury, the club has confirmed.
Fofana, who joined the Blues from Leicester for £70million last summer, endured a frustrating debut season at Stamford Bridge, with a major knee problem restricting him to just 15 Premier League appearances.
And after returning to feature heavily in the final few months of the campaign, the Frenchman has now suffered another fitness setback after damaging his anterior cruciate ligament.
In a statement on Tuesday, Chelsea confirmed Fofana has had an operation on the ACL injury - yet while no timeframe has been placed on his return, he is likely to spend an extended period on the sidelines.
'Defender Wesley Fofana has undergone anterior cruciate ligament reconstruction surgery,' a Chelsea statement read on Tuesday.
'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.'
The recovery process for an ACL injury typically lasts somewhere between six to nine months, meaning Fofana could now miss a huge chunk of the 2023-24 campaign.
Liverpool defender Virgil van Dijk suffered the same injury back in October 2020 and spent nine months out of action before eventually returning in July 2021.
Fofana's setback comes as a major blow to new Chelsea head coach Mauricio Pochettino ahead of their first Premier League outing against Liverpool in just under three weeks time.
As things stand, Thiago Silva and Trevoh Chalobah are now Pochettino's only fit senior centre-backs, with Levi Colwill also available after returning from his loan spell at Brighton.
Colwill, 20, is expected to stay at Stamford Bridge this season and become an important member of Chelsea's senior team after impressing both at Brighton and during England Under 21s' European Championship triumph this summer.
Benoit Badiashile was left out of the Blues' US tour as he continues to recover from a hamstring injury, while Malang Sarr is likely to leave on loan again after his stint at Monaco.