Chelsea captain John Terry is to undergo surgery on his injured right knee and faces several weeks on the sidelines, several English media outlets reported.
In a major blow to Chelsea's Premier League and Champions League campaigns, the inspirational defender could be out of action for up to eight weeks after his injury failed to heal as expected.
Terry suffered the injury after colliding with a goalpost during last month's FA Cup victory over Portsmouth at Stamford Bridge.
The 31-year-old had travelled to Italy for Tuesday's last 16 first leg match against Napoli but was ruled out after suffering a reaction following a training session on Monday.
Terry's injury also has implications for England's Euro 2012 preparations, ruling him out of the February 29 friendly against Holland at Wembley and leaving him racing to recover his fitness for the finals in Poland and Ukraine.
Chelsea have not kept a clean sheet or recorded a victory since Terry was first ruled out injured three weeks ago.