Billy Vunipola could miss England's clash with Fiji with mystery injury
Billy Vunipola is a significant doubt for Saturday's match against Fiji with an injury described cryptically by England as "upper body soreness".
World player of the year nominee Vunipola is unable to train until Thursday at the earliest because of the mystery ailment sustained in Saturday's 37-21 victory over South Africa and a question mark hangs over his availability for the second autumn international.
A heavyweight collision with Eben Etzebeth forced the giant Springbok lock to withdraw from the Twickenham showdown just after the half hour mark and he has been ruled out against Italy with concussion, but England insist Vunipola's injury is not head related.
An update on Vunipola's fitness is expected on Wednesday morning and Eddie Jones will not want to lose one of his vice-captains and a star performer in the 10-Test winning run established on his watch.
The 24-year-old Saracen, a devastating ball carrier with good footwork and an ever-present under Jones, will be replaced at number eight by Nathan Hughes if he fails to recover in time.
Vunipola made way for Dave Attwood with 10 minutes of the autumn opener against South Africa remaining, but the Bath lock will play no part against Fiji after sustaining a knee injury during his brief cameo.
Attwood will return to the Recreation Ground having received treatment at England's Surrey training base, but the injury is not thought to be serious and he could be back to face Argentina on Saturday week.
"We've got a few bumps and bruises. Dave Attwood is having his knee treated. He's having an injection on his knee and is then returning to Bath, so is unavailable," forwards coach Steve Borthwick said.
England have opted against drafting Josh Beaumont into the squad to cover for Attwood and will instead rely on Charlie Ewels, who is already with the team.
Hughes won his maiden cap off the bench against South Africa, with prop Kyle Sinckler and centre Ben Te'o also blooded for the first time. Borthwick believes the trio are ready to start against Fiji if required.
"They all did very well. What was noticeable for me was the ovation the players got from the supporters as they were leaving the field," Borthwick said.
"When the guys came on for their own cap the cheer they got was brilliant and that's a big moment in any player's career.
"They did really well and it improves the competitiveness in our squad, making selection harder, which is what Eddie wants.
"All three players bring a lot of power and explosiveness to the field. They have some special talents and now they've experienced the Test arena. They'll get better and better the more experience they'll get."