Fly-half Marcus Smith is a major doubt for England's Six Nations opener against Italy in Rome on Saturday after picking up an injury in training.

His absence could open the door for Northampton's Fin Smith, 21, to make his debut at the Stadio Olimpico.

An update on Marcus Smith, who also played at full-back during the World Cup, is expected on Tuesday afternoon.

England are already without the whole of the midfield axis that helped them to the World Cup semi-finals and an eventual third-placed finish.

Fly-half Owen Farrell is unavailable for personal reasons, Joe Marchant is ineligible having moved to France, while Ollie Lawrence and Manu Tuilagi are injured.

The retired Courtney Lawes has also left a void in the back row, as has the injured Tom Curry, while Jonny May's retirement has opened up a spot on the wing.

It means head coach Steve Borthwick is set to name a handful of new caps in his matchday squad, with Fin Smith's Northampton team-mate Fraser Dingwall likely to start at inside centre.

However, England captain Jamie George says he has total confidence in whoever is selected.

"I've been so impressed with what I've seen from the boys," George told the Rugby Union Weekly podcast.

"But I kind of knew that coming into camp because of the way the English teams have performed and the competition in the Premiership."

"The excitement and the opportunity in this squad is phenomenal," added scrum-half Danny Care.

"I've always said this team is going to take off after the World Cup."

England will confirm their matchday squad to face the Azzurri on Thursday evening.