Former Stormers lock Quinn Roux will make his debut for Ireland when they face South Africa in the second Test at Ellis Park on Saturday.
Joe Schmidt's men become the first Ireland side to win the Springboks in South Africa when they beat the two-time world champions 26-20 last week at Newlands.
A win for them in Johannesburg this weekend will not only be their first series win in South Africa but they will also become the first Home Nation to achieve this remarkable feat.
The 25-year-old Roux, who moved to Leinster in 2012 from the Cape Town-based side, has since then signed a contract with Connacht in 2015.
A mini battle will be on the cards as Roux will go head-to-head with his former second row partner, Eben Etzebeth.
Schmidt, who coached Roux at Leinster during 2012 and 2014, promoted the second-row to the starting line-up and he expects a fierce backlash from the Boks.
"I think one of the things for us is Quinn very much a very good set piece player," said Schmidt.
"In the scrum and line-out, I think he's very proficient in those two areas and he's trained incredibly well since he's been with us.
"I know Quinn very well from having coached him for two years previously (at Leinster) and during those two years he struggled to get real rhythm because he had a number of injuries and every time he got back playing, he unfortunately didn't get the opportunity to have a succession of games that would have allowed him I think to progress.
"We've seen a bit of that progress in Connacht this season and I guess we're challenging him to progress a bit further in that international arena."
The New Zealand-born coach has beefed up his forward pack, which also includes Leinster prop Tadhg Furlong, who replaces Mike Ross in the front row.
"It is a big day for Tadhg," added Schmidt.
"I know that he and Quinn and Iain Henderson on that axis at the scrum will be working incredibly hard to be as combative and as effective as possible.
"Tadhg is another guy who has trained incredibly well. Tadhg has spent a fair bit of time with us without getting a massive amount of time with us out on the actual pitch.
"He started the season with us at the World Cup, he's remained with us throughout the season and so it's a huge ask for him, but we wouldn't do it if we weren't confident that he can step up and deliver something.
"It's a whole different realm stepping into the lion's den."