Adam Jones has urged the Welsh public to turn up in numbers on Saturday to see their RBS 6 Nations heroes at the Millennium Stadium.
The Judgement Day clashes will see Newport Gwent Dragons take on the Scarlets and Cardiff Blues challenge the Ospreys.
And Jones, who clinched his fourth Six Nations title two weeks ago reckons the double-header will be a great occasion for Welsh rugby.
"It's going to be brilliant," said Jones.
"England started something similar a few years ago and it began with 30,000 fans, but has really grown - it's a good idea and something we're now trying to build up.
"There's always a full house when we play the Scarlets and the other Welsh regions, so it's a good chance to get a lot of the fans down to the ground, and also a great opportunity to give those who didn't see a Six Nations home game to come down to the Millennium Stadium.
"Everyone knows how hard it is to get tickets, and this provides an opportunity for fans to see four good sides."
Jones will go up against a number of his Wales teammates in the showdown, including Six Nations Player of the Championship Leigh Halfpenny.
The Ospreys are well aware of the threat Halfpenny, and his siege-gun boot, pose but he reckons his side can flourish in Cardiff.
"The Welsh players who are playing this weekend are all excellent," said Jones.
"Leigh Halfpenny is one of the best players around at the moment, but we've just got to focus on our own game - it's down to ourselves.
"If we turn up on Saturday and play to the level that I know we can, we can hopefully get the win which is needed."
Ticket sales for the thrilling RaboDirect Pro12 double-header have already surpassed the 30,000 mark, and Jones expects a red-hot atmosphere.
"I've played at the Millennium Stadium before with that amount of people and it's always been a good atmosphere," added Jones.
"Hopefully it will be similar this time around with the roof shut, and the fans can provide a good atmosphere on the day."
The Ospreys are currently in fourth the league table, level on points with the Scarlets, who face the Dragons in the first match of the afternoon.
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The Scarlets Premiership Select XV will be hoping to build on their bonus point victory at Nottingham in the first round of the British & Irish Cup last weekend when they welcome Richmond to Llandovery's Church Bank ground this weekend (Saturday, 2.30pm).
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The latest news, results and tables from the Scarlets region