Chelsea defender Ricardo Carvalho is facing three weeks on the sidelines after limping out of Wednesday night's 3-0 victory over Hull City.
Blues boss Luiz Felipe Scolari revealed his Portuguese defender sustained a thigh injury near the end of the game at the KC Stadium and will be out until November.
The absence of the 30-year-old, who only returned to action last week after a month out with a knee ligament injury, is blow for Chelsea as they attempt to keep pace with Premier League leaders Liverpool.
Carvalho is the first choice to partner John Terry in the centre of defence but he is expected to miss three league matches against Sunderland, Blackburn Rovers and West Bromwich Albion, the Champions League game against Roma plus the Carling Cup tie with Burnley.
Brazilian centre-back Alex is likely to return to the side after providing cover during Carvalho's previous injury lay-off.
Meanwhile, Scolari is hopeful that hopeful that England midfielder Joe Cole will be fit to face Sunderland at the weekend even though the player was substituted after feeling pain in his ankle.