Shane Byrne expects South Africa to play 'beat 'em up rugby' at the Aviva Stadium on Saturday afternoon as Allister Coetzee's side desperately try to prove their star is rising.

Although the Boks come to Dublin seeking a first win in five games, two Rugby Championship draws against Australia and a one-point loss to the All Blacks improved morale.

Ireland bloodied their nose with a historic first win on South African soil last year; now they'll get their chance for revenge. 

"In 2016 they had an absolute nightmare of a season," Byrne told RTÉ 2fm's Game On.

"Yes, they are rebuilding from there. They have really improved. They've gone back to the old traditional style of South African rugby which is basically just beat them up up front and if that doesn't work well beat them up even more.

"It's working for them. It's going to be an absolutely massively physical game because the route one is exactly what they're going to want to do.

"I don't think it's going to be won in the packs, I think the packs will find parity. We have a new centre partnership and they have a new centre partnership as well and it's going to be how those guys get on that will dictate this game."

Byrne still expects the hosts to flex their muscles.

With Bundee Aki set to make his Ireland debut in the centre alongside Robbie Henshaw, Jacob Stockdale lining out for his first home start on the left wing and Darren Sweetnam on the bench, there's an exciting freshness to Ireland. 

"It's a huge Irish side with massive talent," added Byrne.

"Lions all over the place, and some really exciting new combinations like Stockdale on the wing, who's really forced himself into position. There's a lot to watch out for.

"Their form away from home is dire. Ireland are ahead of them in the world rankings, if South Africa win they leapfrog us. So there's a lot at stake. 

"You can add into that the little bit of mud-slinging the committees have been doing to each other with the World Cup bid as a sideshow.

"South Africa are aiming to prove that what they did against the All Blacks, who had already won the Rugby Championship, wasn't just a flash in the pan and they are really taking steps back to where they see themselves."

Ireland v South Africa (5.30pm kick-off), live on RTÉ 2 and the RTÉ Player from 4.30pm & on RTÉ Radio 1's Saturday Sport, with a live blog on RTÉ Online from 4.30pm.