England scrum-half Jack van Poortvliet is out of the World Cup after it was confirmed he will need ankle surgery on the injury he picked up against Wales on Saturday.

Van Poortvliet started every game of the Six Nations and appeared to be Steve Borthwick’s first choice nine but has been replaced in the 33-man squad for the Rugby World Cup by Northampton Saints’ Alex Mitchell. Mitchell had been in England’s World Cup camp at the start of the summer before being cut.

Read more:Farrell red card puts World Cup in doubt after England discipline disaster

Van Poortvliet was helped from the field in the first half at Twickenham with an ankle problem after appearing to trip over team-mate Ollie Lawrence’s feet in the 19-17 victory over Wales. It is a huge blow for the 22-year-0ld who has enjoyed a fast rise from England U20 captain to senior starter in the space of two years.

After the news was made official, England head coach Borthwick said: “It’s really bad luck for Jack. We send him our very best wishes for a swift and successful recovery.”

The other two scrum-halves in Borthwick’s 33 are Ben Youngs, England’s most capped male player, and fellow experienced operator Danny Care, 36. They will soon be joined by Mitchell who now gets the chance to try and force his way into the matchday 23 during the tournament in France.

Related: England Rugby World Cup squad

England are still sweating on the availability of captain Owen Farrell who saw his yellow card for a dangerous tackle upgraded to red on Saturday and is set to face a disciplinary on Tuesday. Farrell could miss the entire pool stage if he receives a six-game ban while a four-game ban would rule him out of the important Pool D clashes against Argentina and Japan.

Farrell has already attended World Rugby’s tackle school and the game’s global governing body confirmed a player is unable to attend the course twice, meaning the England captain will not be able to reduce his ban by a week.

England travel to Dublin to face Ireland on Saturday before their final World Cup warm-up game against Fiji at Twickenham on 26 August. They kickstart their World Cup campaign against Argentina on 9 September.

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