Ospreys may have ended the year atop the GUINNESS PRO12 following victory over Scarlets last weekend, but head coach Steve Tandy admits his side need to raise their game for the return fixture on Saturday.

Despite tries from Aisea Natoga and Dan Lydiate on his first Opsreys start, the hosts failed to build on an eight-point half-time lead but held on to secure a 17-15 win at the Liberty Stadium.

With Ospreys looking to do the double over their rivals at Parc y Scarlets on Saturday, Tandy has made one change to his starting line up with Natoga replacing Eli Walker, who is out with a hamstring injury.

Props Ryan Bevington and Nicky Smith are still absent with long-standing injuries but lock James King will make his 100th appearance for the region.

And Tandy has urged his players to guard against the complacency that crept in during last week’s game if they are to extend their winning streak against Scarlets to six consecutive matches.

“It was pretty much mixed emotions last weekend,” he said.

“Obviously we were pleased to win the big derby match in front of our own fans at the Liberty, and to end the year at the top of the table, but there was a huge feeling of disappointment at the performance.

“The dressing room was fairly downbeat after the game as there was a realisation that we didn't reach the desired standard.

"The focus this week in training has been about getting back to basics and doing the small things correctly. We know that it's going to be tough down there on Saturday. There'll be a big crowd and Scarlets’ tails will be up given our poor performance in the second half.

“We have worked hard to put ourselves in the position we are in the PRO12 table and it's important that we keep striving for excellence, pushing ourselves to be better each week so that the hard work doesn't go to waste.”

While Ospreys have gone unbeaten in their last 17 Welsh derbies, the visitors will be tested by a Scarlets team that have suffered only one defeat in their last 15 matches in all competitions at Parc y Scarlets.

Centre Scott Williams returns to captain his side, with Hadleigh Parkes moving from centre to wing and Michael Tagicakibau joining Parkes and Liam Williams in the back three.

Hooker Kirby Myhill replaces the injured Emyr Phillips, Johan Snyman joins Jake Ball in the second row and scrum-half Gareth Davies returns to the bench following a long lay-off with a knee injury.

And Scarlets head coach Wayne Pivac is confident his side can draw on a fervent home support to reclaim some bragging rights over their high-flying rivals.

"We wanted to build a fortress at home and we've continued with the good form at home that Simon (Easterby) had handed over and we've remained unbeaten at home,” he said.

"The boys love playing at home. A supportive home crowd is worth a good few points to us.

"It's a big game, a big challenge for us but certainly we haven't lost focus on the fact we need to get a win.

"All games are important but winning the games at home are a priority and getting maximum points from them."

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At Parc y Scarlets, 5.05pm. Live on Sky Sports and S4C
Referee: John Lacey (IRFU, 41st competition game)
Assistant Referees: Ian Davies, Marty Lewis (both WRU)
Citing Commissioner: Aurwel Morgan (WRU)
TMO: Tim Hayes (WRU)