England number eight Billy Vunipola could miss the Six Nations with a suspected broken forearm sustained during Saracens' win over Racing 92.

It would be the fourth such injury for Vunipola in two years, having broken his right arm twice and his left once.

The 27-year-old played every game in England's run to the World Cup final, but is set to miss out when Eddie Jones names his Six Nations squad on Monday.

"They suspect a broken arm," said Saracens director of rugby Mark McCall.

"I hope it's not. I don't think it's been confirmed yet."

Vunipola left the field in the sixth minute of Saracens' win, which could see them advance to the last eight of the Champions Cup.

His possible absence boosts Harlequins back row Alex Dombrandt's chances of an England call-up, while Saracens' Ben Earl, Sale's Ben Curry and Exeter's Sam Simmonds have also been impressing in the Premiership and Europe.