Harlequins back row Jack Clifford will miss England's November internationals due to an ankle injury which requires surgery.
The 23-year-old did the damage during a Premiership defeat at Exeter Chiefs last weekend and is expected to be out of action for 10 weeks.
Clifford, who was handed an international debut by Eddie Jones during the Six Nations this year and has gone on to win eight caps, will play no part in England's clashes with South Africa, Fiji and Argentina in November.
He also looks likely to miss out against Australia at Twickenham on December 3.
The loss of Clifford is a major blow for Quins, who have won just one of their first three Premiership matches this season and have European Challenge Cup games against Stade Francais and Edinburgh to come next month.
"It is very disappointing and unfortunate that Jack has sustained his injury," Quins director of rugby John Kingston said.
"He is a fierce competitor and I have no doubt he will work exceptionally hard to get himself back on the field as quickly as possible."