The 31-year-old tore a muscle in his left thigh during training ahead of the friendly with Brazil in Qatar this weekend and has already flown home for further treatment.
- England home
- Chelsea home
A short statement on the Blues' official website read: "It has been confirmed that Frank Lampard suffered a muscle tear in his left thigh while away with the England national team.
"He reported back at Cobham this morning having flown back from the Middle East. The Chelsea medical department's initial impression is that he may take approximately three weeks to recover."
Some press reports earlier in the day had suggested that Lampard could be out for a couple of months, but Chelsea expect the recovery period to be much shorter.
He is still likely to miss league games against Wolves, Arsenal, Blackburn Rovers and possibly Manchester City, as well as a Champions League clash with FC Porto.