Cardiff Blues winger Tom James feels events like Judgement Day are the reasons he and many players get into playing rugby.

James has yet to taste the double-match extravaganza, but is anticipating an exciting clash against Ospreys at Principality Stadium come Saturday.

But there are more important reasons for a win than just Welsh pride and fun experiences for a Blues side still bidding for a Guinness PRO12 top six finish this season.

"It will be a bit different, a different atmosphere, only with Wales have I played in front of 72,000 and if we can get that attendance it will be awesome,” said James.

"That's why you play rugby, for atmospheres like that, all the fans will be out in force and there will be a big buzz.

"Hopefully we can do this on a regular basis. If we can play well the fans will turn up week in, week out. If we carry on as we are then they will come out all the time."

Lloyd Williams and Rhys Patchell have not recovered from injuries for the Blues, replaced by Lewis Jones and Aled Summerhill while Matthew Rees and Josh Navidi also come into the team.

While the Blues have won five of six Wales derbies this year, Ospreys have not lost against Danny Wilson’s side for the last nine matches.

And Ospreys head coach Steve Tandy insists the day will mean nothing if his Ospreys can’t keep their top six hopes alive.

“There’s no doubt it’s going to be a great occasion for regional rugby on Saturday. It’s fantastic to see a record crowd coming out to watch the four regions in action and it will no doubt be a great atmosphere,” he said.

“However, it’s important that we don’t get distracted by the occasion and everything that comes with it.

“We have to be 100% focused as a team on the job in hand and while it's a special occasion for the supporters, we have to remember that we have a job to do. It won’t be enjoyable or memorable if we don’t get the right performance.

“The hope is that with such a large crowd in Cardiff on Saturday, with many who clearly aren’t season ticket holders at a region, they’ll be impressed by what they see and want more.

“If we get the performance right on Saturday, Ulster a week later is a massive game and we would love some of them to come to the Liberty and be part of another great occasion.”

Ospreys make four changes from victory over Treviso, with Scott Baldwin coming in at hooker, Dan Lydiate starting at No.8 and Eli Walker and Jonathan Spratt named in the backs.

At Principality Stadium, 2.30pm. Live on BBC Wales
Referee: Nigel Owens (WRU, 134th competition game)
Assistant Referees: Leighton Hodges, Martyn Lewis (both WRU)
Citing Commissioner: Dennis Jones (WRU)
TMO: Jon Mason (WRU)