England full-back cum wing Ben Foden is set to miss the start of the Six Nations after suffering a knee injury while playing for Premiership side Northampton.
The 28-year-old suffered the setback in the Saints' 18-0 win over Newcastle last month and Northampton coach Jim Mallinder says he isn't likely to return until February and at the earliest.
The estimated 12-week period puts him in doubt for the start of the Six Nations, which begins in the first weekend of that month.
"It's very unfortunate for him," Mallinder told the European Rugby Cup website.
"He's very confident he can get back before then, he's always positive, which is good, so we'll have to see how that goes.
"He's in a positive frame of mind. It could have been worse, it could have been better. Ben is a quick healer but you cannot rush these things."
Foden has fallen down the England pecking order at full-back behind incumbent Mike Brown and Alex Goode.
But his versatility gave him his 34th Test cap as a wing in England's most recent international - last month's 30-22 defeat by world champions New Zealand at Twickenham.
He joins an England injury list that includes back-row Tom Croft, centre Manu Tuilagi, Northampton prop Alex Corbisiero and lock Geoff Parling, all of whom are set for lengthy spells on the sidelines.
