Cardiff Rugby's Williams, who returned from injury to feature in Round 4 of the EPCR Challenge Cup and is likely to be a key figure in his side's Round of 16 encounter with Sale Sharks, steps in for Scarlets' Halfpenny after he suffered a back spasm.

Halfpenny was set for his first start for Wales for 19 months after recovering from a knee injury and showcasing his qualities in this season’s EPCR Challenge Cup, kicking 15 points in three games as Scarlets topped Pool B and set up a Round of 16 clash with CA Brive in Llanelli.

Wales head coach Warren Gatland has selected seven EPCR Challenge Cup players to start, with Cardiff Rugby wing Josh Adams included after scoring four tries in the pool stage.

Dragons RFC wing Rio Dyer gets the nod after his score against Emirates Lions in Round 3, while Dan Biggar is at fly-half after contributing 24 points as RC Toulon finished top of Pool A.

Cardiff Rugby are represented by scrum-half Tomos Williams and No.8 Taulupe Faletau, after they came third in Pool A, while Scarlets hooker Ken Owens captains the team.

Two further EPCR Challenge Cup players make the bench in Cardiff props Rhys Carré and Dillon Lewis.

Liam Williams has replaced fellow EPCR Challenge Cup star Leigh Halfpenny at full-back for Wales in their Six Nations opener against Ireland in Cardiff on Saturday.