Wales star Liam Williams will miss next weekend’s opening Test against Australia with an ankle injury - opening the door to an immediate return for Leigh Halfpenny.

Sportsmail understands Williams, who was player of the series against New Zealand, was placed under anaesthetic on Monday night to determine the extent of the ligament damage.

The Scarlets full-back faces at least two weeks out, but could miss the entire campaign if medics decide the 25-year-old requires surgery after an over-rotation.

Liam Williams will miss Wales' opening Test against Australia with an ankle injury

Wales star Williams suffered ligament trouble when the Scarlets faced Saracens in Europe

Williams (No 15) makes a tackle on Schalk Brits in last weekend's Champions Cup clash

WALES' AUTUMN TESTS November 5: Australia (2.30pm) November 12: Argentina (5.30pm) November 19: Japan (2.30pm) November 26: South Africa (5.30pm) Advertisement

Williams had been tipped to retain the No 15 jersey ahead of Halfpenny, who has not played international rugby since suffering a horror knee injury before the World Cup.

While interim coach Rob Howley must deal with the latest setback, he has been boosted by the availability of Jamie Roberts and George North – subject to a hand injury.

Premiership Rugby had previously stated that English-based stars are ineligible for the out-of-Test-window opener but confirmed the one-off move as a ‘gesture of flexibility’.

The exemption also frees Ross Moriarty, Tomas Francis and Luke Charteris to feature against the Wallabies, but No 8 Taulupe Faletau will still be sidelined by injury.

Sportsmail understands Faletau is out of a protective brace and is targeting a comeback in mid-November.

The Scarlets full-back will be a big miss for Wales given his supreme recent performances