Vunipola started the competition impressively, picking up a man-of-the-match award in their opening game with Ireland at the Aviva, a 32-20 win.
He sustained the injury during England’s 44-8 win over France at Twickenham on Sunday, coming off in the 44th minute.
In a statement the RFU said “Following medical assessments Mako Vunipola (Saracens) has been ruled out of England’s Guinness Six Nations campaign with an ankle ligament injury.
“Vunipola picked up the injury during England’s win against France on Sunday and is expected to be out for 10 weeks.
“The England prop will begin his rehabilitation with his club Saracens.
England head coach Eddie Jones said: “It is obviously very disappointing to lose Mako at this stage as he is an important player for us but it does provide an opportunity for the team to grow.”
— England Rugby (@EnglandRugby) February 12, 2019
But Vunipola’s absence will be a huge loss, he is ranked as the world’s number one loosehead prop in the RugbyPass Index with an RPI of 90.
Vunipola also missed the entire autumn series due to a calf strain.
England will assemble in central London on Wednesday lunchtime for a three-day camp ahead of their next match against Wales on the 23rd February in Cardiff.
Watch: Eddie Jones “We are playing the greatest Welsh side ever”
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