England have called Matt Kvesic, Mouritz Botha and Ugo Monye to their Six Nations training camp as injury cover.
Worcester flanker Kvesic, 20, will be hoping for his first senior appearance while Saracens lock Botha is recalled having been a regular fixture in last year's competition.
The trio step up to Stuart Lancaster's squad due to concerns over Exeter flanker Tom Johnson (knee), Northampton forward Calum Clark (shoulder) and a number of backs involved in some bruising European fixtures over the weekend.
Kvesic told Worcester's official website: "I have been fortunate to have a run of games at Warriors, and now I am delighted to get the call from England.
"It would be fantastic to get the opportunity to feature in the Six Nations, but my priority now is meeting up with the team, keeping my head down and working hard to try and make that a reality."
Harlequins wing Monye will also train with the group as several men involved in European action over the weekend are assessed by medical staff.
England kick off their Six Nations campaign at Twickenham on 2 February when they face Scotland, who will be prepared for the game by interim head coach Scott Johnson.
Jamie Gibson of London Irish replaces Kvesic in the England Saxons squad for their games against Ireland Wolfhounds in Galway on 25 January and Scotland A at Kingston Park seven days later.