England boss Eddie Jones will put Courtney Lawes' health first after hinting his captain will not return from a concussion during the current Autumn Nations internationals.
Lawes is yet to return to action having suffered a head injury in Northampton's defeat by Leicester on September 24.
With the veteran flanker still symptomatic as he progresses through the concussion protocols, Jones has effectively ruled him out of the remaining Autumn Nations Series fixtures against Japan, New Zealand and South Africa.
Lawes already has a history of concussion, including a six-week spell out earlier this year.
"There's no movement with Courtney at the moment," Jones said on Tuesday.
"Initially I kept in touch with Courtney but given that he needs some rest now rather than feeling like he has to rush to come back, we are allowing it to take its natural course.
"We are in communication with his medical staff but we are letting him rest and come back. We're hopeful that he will be back for the Six Nations and ready to go.
"I'm worried about his health at this time -- that he gets back to 100 percent health. But these things have a natural course -- some heal quicker than others.
"If it takes a little bit of time, the most important thing is his health and he'll get back to playing rugby when he's ready."
With Lawes sidelined, Owen Farrell will continue as England captain as they aim to bounce back from their first loss to Argentina since 2009.
Jones has taken responsibility for that dismal display, admitting that he had allowed planning for next year's World Cup to distract him.
"Maybe our focus wasn't tight enough on the Argentina game," Jones said.
"When I reflect on the game, we'd been looking at a number of long-term strategies that we're trying to employ to get ourselves set for the World Cup.
"We looked at times like we lacked a bit of energy, particularly in our attack. Maybe we're just overthinking a bit. That's entirely my fault."