England number eight Ben Morgan looks set to miss the entire RBS 6 Nations after breaking his leg in Gloucester's Aviva Premiership victory over Saracens on Friday night.
Morgan suffered the injury in the second half at Kingsholm and while no timeframe for his return has been given by his club, he is unlikely to play any part in the Championship.
"Morgan has suffered a fracture to his lower left leg and had surgery performed on Saturday morning. He will commence an appropriate rehabilitation programme for this type of injury over the coming weeks," read a statement released by Gloucester.
Morgan was among England's stand-out performers in the recent autumn series, in which he displaced Billy Vunipola to become first-choice number eight.
The 25-year-old scored two tries against Australia and one against South Africa with his ball-carrying proving a key asset for Stuart Lancaster's men.
Vunipola is likely to start at number eight in the Six Nations opener against Wales in Cardiff on February 6.