Chelsea captain John Terry has been ruled out for up to two months after aggravating his knee injury, Press Association Sport understands.
Terry is due to undergo what is understood to be a small procedure on the right knee that has been troubling him ever since he collided with a post in last month's FA Cup clash with Portsmouth.
Blues boss Andre Villas-Boas had been hoping the 31-year-old would recover in time for tonight's Champions League clash at Napoli.
But, despite taking part in training last night, the England centre-back woke up in considerable pain at Chelsea's team hotel this morning and will now miss tonight's game and next week's international friendly against Holland.
The news is huge blow to the club, who have not won a match or kept a clean sheet since Terry was first ruled out three weeks ago.
A two-month absence would see him miss potential Champions League and FA Cup quarter-finals as well as a host of crucial Barclays Premier League games as Chelsea struggle to secure a place in the top four.
Terry had played through the pain of what was bruising on the bone for three weeks and the club were hoping a period of rest would see him make a full recovery.
But he is now set to undergo a small procedure in the next 24 hours after the Blues fly home from tonight's Champions League last 16 first leg.
England caretaker manager Stuart Pearce is scheduled to name his squad for next Wednesday's friendly with Holland on Thursday morning.
Terry's absence relieves Pearce of the problem of having to decide whether to pick both the deposed captain and Manchester United defender Rio Ferdinand.
Terry lost the armband while he awaits trial for allegedly using a racist slur against Ferdinand's brother, QPR's Anton Ferdinand.
Terry denies any wrongdoing and the Football Association's decision to strip him of the captaincy led to Fabio Capello quitting as England boss almost two weeks ago.