Leicester director of rugby Richard Cockerill says Manu Tuilagi will miss England's first two Six Nations matches but has stopped short of ruling the centre out of the entire tournament.
Tuilagi, 23, cast doubt on his hopes when he said he did not know when he would return from a groin injury.
England play Wales in Cardiff on 6 February and host Italy on 14 February.
"Manu won't be fit for the Wales or the Italy games but after that we'll have to see," Cockerill told BBC Sport.
"He's improving slowly and it's getting better day-by-day," Cockerill added. "It's been a difficult one, we want him back 100%."
Tuilagi has been out since October with the problem and missed England's autumn internationals.
He suffered a recurrence of the injury in Leicester's European Champions Cup win over Ulster on 18 October.
|England Six Nations fixtures|
|6 Feb: Wales v England, 20:05 GMT|
|14 Feb: England v Italy, 14:30 GMT|
|1 Mar: Ireland v England, 15:00 GMT|
|14 Mar: England v Scotland, 17:00 GMT|
|21 Mar: England v France, 17:00 GMT|