London - England suffered yet another injury setback when flyhalf Owen Farrell was ruled out of the entire Six Nations Championship on Tuesday with a knee ligament injury.
The stand-off, who can also play at centre, was assessed by England medical staff on Monday and the Rugby Football Union confirmed on Tuesday he had suffered a "high grade medial ligament strain that will keep him out for the duration of the Championship".
Farrell, 23, sustained the injury during Saracens' European Champions Cup loss away to Clermont on Sunday when he went off in the 19th minute following a collision with the French club's flank, Julien Bardy.
"It's a real shame for Owen that he sustained this injury and we wish him the best for his recovery," said England coach Stuart Lancaster in a RFU statement.
During the November internationals, Farrell, son of England backs coach Andy Farrell, lost his starting place at No 10 to George Ford and England also have two more flyhalves in their squad in Stephen Myler and Danny Cipriani.
However, the trio have only 16 caps between them, compared to Farrell's 29 England appearances.
"We are fortunate to have three other No 10s in the squad in what is a very competitive position and we will look forward to seeing how they go over the Six Nations," said Lancaster.
England, who will stage the 2015 World Cup later this year, had already seen powerhouse centre Manu Tuilagi sidelined with a groin problem ahead of their Six Nations opener away to Wales in Cardiff on February 6 while fellow midfielders Brad Barritt (knee) and Kyle Eastmond (shoulder) are other backline injury concerns.
Meanwhile, Northampton centre Luther Burrell suffered concussion against Racing Metro but hopes to resume full training later this week.
Up front, flank Tom Wood and lock Geoff Parling sustained ankle and knee injuries respectively in a gruelling round of European action.
England were already without No 8 Ben Morgan (leg) and second row Joe Launchbury (neck) for the Six Nations while lock Courtney Lawes has been ruled out for the first few weeks while he recovers from ankle surgery.
"We will continue to assess and treat the other players' injuries and will provide an update at the (tournament) launch tomorrow (Wednesday)," said Lancaster.