The England flanker Tom Wood is free to play in Saturday’s World Cup match against Australia after being warned for striking Wales full-back Liam Williams in Saturday’s match at Twickenham.

Williams received several minutes of treatment before being driven from the pitch on the medical cart and is a doubt for Thursday’s match against Fiji, although the initial signs are that he is making encouraging progress from the concussion he sustained.

England will be relieved to have their first-choice blindside flanker available to face the Wallabies, knowing that only victory will be enough to save their World Cup following the 28-25 defeat by Wales.

“Under the Rugby World Cup 2015 disciplinary programme, a citing commissioner warning equates to a yellow card in sanction,” read a statement released by tournament organisers.

“A combination of three yellow cards or citing commissioner warnings accumulated during the tournament will result in a hearing. Wood is therefore free to play in England’s next Pool A match against Australia.”

Wood apologised to Williams after saying he felt guilty for knocking out the Wales full-back as he attempted to kick the ball which resulted in a heavy collision with Wood’s shin.

Williams was carried off the field on a stretcher in the 67th minute after being knocked unconscious for several minutes.