Head coach Warren Gatland has recalled Biggar and scrum half Mike Phillips to the pivotal half back positions with Alex Cuthbert also a welcome addition after a quick recovery from an ankle injury.
Successive wins over Argentina and Tonga have placed Wales in confident mood but as is commonly known, their recent record against Australia isn't the best. The Wallabies last tasted defeat against the men in red back in 2008 and beat Wales four times in 2012.
This time around, there seems to be a different mood. Australia are on the back of a long season, one which included a 2-1 series defeat to the British & Irish Lions. Two men who didn't feature in that famous series were Biggar and Cooper but both will be key for their respective sides today.
Melbourne Reds playmaker Cooper seems reinvented since being handed the Australian vice captaincy by new coach Ewen McKenzie and his opposite number knows just how dangerous he can be.
"If you look at Australia in the last three months and certainly on this tour, they're coming into form and that's down to Cooper at 10," said Biggar.
"He gives them direction and that bit of spark - he's going to win his 50th cap and that's a special achievement. For me he's one of the best fly halves in the world.
"He's got all the talent and now he's back in the team, I think they're a much better side. They look a lot more confident with him and Will Genia at nine and 10.
"The first step is to stop him getting on the front foot as when he does that, he's very dangerous."
Wales have shared the fly half jersey around this autumn. Priestland started the opening clash with South Africa while Biggar began the comfortable defeat of Argentina. Perpignan man James Hook got the nod against Tonga last Friday.
"Rhys' form has been excellent so far and it's a big vote of confidence for me to get the nod and go out there and to perform," said Biggar.
"It's nice we're both fit now and vying for competition in the squad. We get on very well away from the field, we're pushing each other and that's only going to benefit both our games. With Rhys coming back fit, I knew I had to keep sharp and keep working on things day in and day out.
"It was a nervous wait, until your name is read out you're not entirely sure but it was a proud moment and I'm really looking forward to it.
"I feel good in myself, that's a massive plus. What I've tried to do this year is do the little things just that bit better, do the basics well and maybe one or two other things will fall into place.
"It's a chance I'm looking forward to grasping."
Wales' last meeting with Australia was a 14-12 defeat to the Wallabies last December. Gatland's men looked to have victory in the bag but a last ditch score from Kurtley Beale saw the men in green and gold take home another win.
Biggar was an unused replacement in that game but like the rest of the Wales squad, knows it's time to turn the tables on their rivals.
"Australia have won so many games against us in the past and we haven't got a good record against them, there's no getting away from that," he said.
"But it's hugely important we put all of that behind us. It's a one off game and a huge, huge opportunity for us to put a marker down.
"We're fed up of saying Wales played well against a southern hemisphere team but lost by two or three points in the last minute. The coaches and players have said it's not good enough to lose on Saturday.
"Australia have probably got one of the best players in the world in Israel Folau, we can't give him time or space. It means we'll have to be a lot more accurate in our kicking game, there will be times when the ball goes to him, that's just the way it goes, but going back to Australia, they have a bit of a swagger about them.
"It's great for us that they're coming to play some rugby and hopefully we can shut them down."