England wing Marland Yarde could miss the entire RBS 6 Nations as he requires surgery to repair a torn hip tendon.
The London Irish flyer suffered the injury in last weekend's 20-11 Aviva Premiership defeat to Leicester and will now miss between 12 and 14 weeks, his club have confirmed.
Yarde featured in England's autumn international clash against Australia at Twickenham, after impressing on the summer tour to Argentina.
Yarde missed England's clashes against Argentina and New Zealand through injury but this fresh blow leaves a big hole to fill in both the Irish and England ranks.
England start their Six Nations campaign against France on February 1, with Yarde now unlikely to be fit in time to make Stuart Lancaster's squad for that tournament opener.
London Irish have also confirmed hooker David Paice will miss eight to 10 weeks after fracturing his radius in that Leicester defeat last week.