George Kruis' fitness continues to be shrouded in uncertainty after it was revealed the England lock is to seek a second opinion over his knee injury.

Kruis sustained ligament damage during Tuesday's training session at the squad's Surrey base, ruling him out of at least the RBS 6 Nations opener against France.

England still retain hope that their main line-out caller will play some role in the Championship, but having seen one specialist for a diagnosis he must consult another.

"George will have some more assessments. We are hoping we'll know more in the next two or three days," scrum coach Neal Hatley said.

"We'll probably know a lot more after the assessment. We haven't given up on having him involved at some stage during the latter part of the Six Nations.

"We want to see what the options are moving forward. It will be the best outcome for the player, what George needs to get George right and back playing.

"The Lions or anything like that are of no significance really for us, it will be more about what George needs and what's good for George personally to make sure he's fit for the rest of the season."

Joe Launchbury replaces Kruis in England's starting XV for France's visit to Twickenham on Saturday, reprising the second row partnership with Courtney Lawes that played against South Africa and Fiji last autumn.

Saracens lock Maro Itoje, who sat out the November series with a hand problem, will be making his first international appearance in the back row in place of Chris Robshaw.

Robshaw will miss the entire Championship because of shoulder surgery and, while Itoje lacks his work-rate, he is more explosive around the pitch.

Joe Launchbury steps in for Kruis (Getty)

"Maro brings so much energy to the side and has played blindside flanker before - we used him there in Australia, so it's not like he's new to the position," Hatley said.

"He walked through things with (defence coach) Paul Gustard this week and if you have watched Maro at any level he brings ridiculous enthusiasm to the team and we can't wait to see him there.