Three wins from three has Scarlets top of the GUINNESS PRO12 table, a position Pivac concedes they are unlikely to hang on to come May.

But a top-four finish is certainly achievable and Pivac believes victory over four-time champions Leinster will really underline their credentials.

"This is a critical game to maintain our position in that top-four group," he said.

"We want to stay top for as long as we can, but for us top four is a new era really.

"Playing at home is a big thing for us. We've already won a home game against an Irish side this season and performed reasonably well. We most definitely want to repeat that.

"We didn't perform well out in Zebre in our last game and then we had to contend with another week's break.
"In terms of improvements from the last performance we've talked about it and very much put Zebre to bed."

Pivac has picked a new-look backline for Friday's clash, which sees winger DTH van der Merwe come in for his debut now Canada's World Cup adventure is over.

Aled Thomas replaces Jordan Williams at full-back and there is a new half-back pairing of Aled Davies and Steven Shingler with Rhodri Williams and Dan Jones moving to the replacements bench.

Kirby Myhill is the only new face in the pack with Emyr Phillips sidelined by a hamstring injury.

Pivac's opposite number Leo Cullen has made five changes to the side that beat Newport Gwent Dragons last time out.

Colm O'Shea replaces the injured Ben Te'o, while Ross Byrne makes his first start alongside Isaac Boss - set to make his 125^th Leinster appearance - in the half-backs.

"Scarlets has always been a tough place for us to go and play, even when we're both full strength," said Boss.

"They play a good brand of rugby and they've got a really good record at home. They've started the season really well, but it's a good chance for us to measure ourselves."

Mike McCarthy and Rhys Ruddock have been called into the Ireland squad, so Tom Denton and Dan Leavy replace them.

Hooker Bryan Byrne makes his first start of the season at hooker and, among the replacements, Jamie Hagan will win his 50th cap for Leinster should he come off the bench.

At Parc y Scarlets, 7.35pm. Live on BBC Wales/TG4
Referee: Peter Fitzgibbon (IRFU, 62nd competition game)
Assistant Referees: Wayne Davies, Greg Morgan (both WRU)
Citing Commissioner: Aurwel Morgan ( WRU)
TMO: Tim Hayes (WRU)