Frank Lam,pard is out of Sunday's clash at Villa Park against Aston Villa.
The midfielder has torn a muscle in his thigh in training today.
A scan in hospital has confimed the goal-scoring midfielder is out of the Midlands clash and is a doubt for England's Euro 2008 match against Israel on Saturday week.
Chelsea confirmed that the tear is in the same leg as his broken toe.
Joe Cole is expected to move from the bench and make his first start in the league for the Blues.