But the Newcastle fly-half is optimistic of being fully fit before the championship ends in March.
Wilkinson has not played international rugby since his extra-time drop-goal gave England World Cup glory against Australia in Sydney 14 months ago.
A serious neck and shoulder problem was followed by a niggling bicep injury, and he is now recovering from knee-ligament trouble that has meant another frustrating spell on the sidelines.
"I am coming on really well. The physios at England and Newcastle are as happy as they could possibly be at this point of the recovery," said England star Wilkinson at the Six Nations Championship launch in London.
"It is really good news. I am really eager to get back playing, but also to make sure the recovery is thorough. My left leg is my kicking leg, and I don't really want any chronic knee problems hanging around if I am going to be smashing balls around for a couple of hours a day.
"Overall, it is massively positive, considering the circumstances, and all I can do is try to get back. It happened two and a half weeks ago and the limit was then set of six to eight weeks, which is the second half of the Six Nations.
"All I can do is free myself up for selection and then see what people want to do with me, whether they want to play me or leave it. I am just concentrating on doing my bit, which is the rehab."
Sale Sharks full-back Jason Robinson will continue to captain England in Wilkinson's absence. But Wilkinson is retaining a healthy interest in England's build-up to the championship, which starts against Wales in Cardiff on Saturday week.
"I am really excited about England's prospects because of the players we have and the ability, confidence and enthusiasm that is there," Wilkinson added.
"There might be some new faces, and I am sure the guys will take their opportunity massively."
This season's tournament is expected to be the most competitive in Six Nations history, with current form suggesting that England, France, Ireland and Wales all have realistic title chances.
"There is no hiding in the Six Nations, whatsoever, for any team," Wilkinson said.
"Every game is one of those when you could be on the wrong end of the scoreline, regardless of whether it is France at home, Wales away or anyone.
"That is important to the success of the Six Nations, and also letting England find a marker of where we stand in terms of how we are coming on as a side."