Saracens and England number eight Billy Vunipola will miss the rest of the season after suffering a knee injury.

Saracens have not disclosed the extent of the injury, but it could affect his World Cup chances in the autumn.

He has won 67 caps since his England debut in 2013, but has not played since the defeat by South Africa in November.

He started all of England's matches at the 2019 World Cup as they were beaten by the Springboks in the final, and also played twice in the 2015 tournament.