Wales captain Alun Wyn Jones will return from a knee injury for Ospreys' crucial Pro14 derby with Cardiff Blues at Judgement Day.

There were fears the 33-year-old would not play again this season after injuring himself in Wales' Grand Slam-clinching win over Ireland in March.

Gareth Anscombe, who joins Ospreys next season, switches to full-back in what could be his final game for the Blues.

Jarrod Evans replaces the Wales fly-half at 10 in one of four changes.

The others see number eight Nick Williams return as captain with Seb Davies reverting to the second row, Lloyd Williams restored at scrum-half and Aled Summerhill replace Jason Harries on the wing.

Fourth place in Conference A is on the line in this encounter - a regular season finish that offers a place in next season's European Champions Cup via a play-off against the team finishing in the same slot in Conference B.

However, there is still a danger of no Welsh region qualifying for the premier European tournament in 2019-20.

Anscombe's involvement is of particular interest, having signed with Ospreys for next season.

"I have no doubts over Gareth's commitment," said Blues head coach John Mulvihill.

"He is the consummate professional and is hugely competitive. He has had a great season here at Cardiff Blues and will want to go out on a high."

On Saturday's game at the Principality Stadium, Ospreys head coach Allen Clarke said: "Our goal for the season has been to achieve Champions Cup qualification.

"We're under no illusions to the challenge and level of performance required against Cardiff on Saturday."

Cardiff Blues: Gareth Anscombe; Owen Lane, Rey Lee-Lo, Willis Halaholo, Aled Summerhill; Jarrod Evans, Lloyd Williams; Rhys Gill, Ethan Lewis, Dillon Lewis, Seb Davies, Rory Thornton, Josh Turnbull, Olly Robinson, Nick Williams (capt).

Replacements: Kirby Myhill, Rhys Carre, Dmitri Arhip, George Earle, Shane Lewis-Hughes, Tomos Williams, Garyn Smith, Jason Harries.

Ospreys: Dan Evans; George North, Cory Allen, Owen Watkin, Hanno Dirksen; Sam Davies, Aled Davies; Nicky Smith, Scott Baldwin, Tom Botha, Adam Beard, Alun Wyn Jones, Olly Cracknell, Justin Tipuric (capt), James King.

Replacements: Sam Parry, Rhodri Jones, Ma'afu Fia, Bradley Davies, Dan Lydiate, Matthew Aubrey, Luke Price, Keelan Giles.

Referee: Nigel Owens (WRU)

Assistant referees: Craig Evans (WRU), Gwyn Morris (WRU)

TMO: Ian Davies (WRU)