Chris Robshaw: Harlequins flanker out of England's Six Nations campaign
Harlequins flanker Chris Robshaw will miss England's 2017 Six Nations campaign with a shoulder injury.
The 30-year-old will have an operation on Monday and is expected to be sidelined for three months.
Robshaw, who has won 55 caps, aggravated a problem with his left shoulder at Worcester on 1 January.
The back row captained the national side between January 2012 and January 2016, but was replaced as skipper after Eddie Jones became England head coach.
Jones led the side to a Grand Slam in 2016 but the Australian has a number of injury worries going into this year's tournament, which England begin against France at Twickenham on 4 February.
Saracens forwards Billy and Mako Vunipola have been ruled out with knee injuries, while Leicester centre Manu Tuilagi is out for the season with cruciate ligament damage.
Lock George Kruis is a doubt with a fractured cheekbone, and flanker James Haskell was concussed on his return from six months out with a foot injury.
Captain Dylan Hartley, who is suspended until 23 January, will need to prove his fitness before the competition starts.
Chris Jones, BBC Radio 5 live rugby union reporter
After losing the captaincy following the World Cup, Chris Robshaw was a talisman for England on the blind-side flank in 2016 - playing in all but one of the 13 straight victories.
He was also repeatedly singled out for praise by head coach Eddie Jones for his outstanding performances.
However, while Robshaw's leadership and consistency will certainly be missed in the Six Nations, it may present Jones with the opportunity to move Maro Itoje from the second row into the back row, especially if locks Joe Launchbury and George Kruis can prove their fitness over the coming weeks.