Pat Lambie.
"I'm excited to see what Pat can bring to the team," said Springbok coach Heyneke Meyer on Wednesday.
"He played very well in the last few weeks of the Absa Currie Cup and hopefully he can bring that momentum with him on Saturday."
Lambie's inclusion at pivot, in place of the injured Johan Goosen, was one of only three changes to the team which started against New Zealand in Soweto last month.
JP Pietersen returned at right wing while Juandré Kruger took over at lock, for Bryan Habana and Andries Bekker respectively, who were both ruled out of the tour because of injury.
"It's also good to have JP back. He's had a great season and will want to finish the season on a high," Meyer said.
"At lock, there has been strong competition for the number five jersey all season and now Juandré gets an opportunity again."
For the first time, the Springboks have named an eight-man replacement bench, in line with the new laws which stipulate that a full front row of two specialist props and a hooker have to be selected.
Returning to Springbok duty for the first time since 2008, Schalk Brits starts on the bench next to CJ van der Linde and Pat Cilliers.
Van der Linde had not appeared for the team since the 2011 Rugby World Cup.
"Schalk is an explosive player who can bring something special off the bench," said Meyer.
"CJ is very experienced and knows the conditions here quite well, as he played for Leinster for two seasons."
Meyer said the match would be a major test in trying conditions for his young team. A temperature of around five degrees was forecast for Saturday afternoon, while winds and a 25% chance of showers were also predicted.
"I've said from the outset that I'd like to see which of the players can handle the Northern Hemisphere conditions on this tour, as it will be the same for the Rugby World Cup in 2015," said Meyer.
"We'll be facing an Ireland team that is never an easy opponent in Dublin. They will also be desperate to get back to winning ways after winning two of their eight Tests this season, which, to my mind, is not a true reflection of how good the Irish really are."
Meyer confirmed today that Leinster prop Heinke van der Merwe has been called up to the Springbok squad for the duration of the tour. He played in his only Test for South Africa against Wales in November 2007, and he toured with the Springboks at the end of the 2009 season.
Gurthrö Steenkamp, who joined the squad on Tuesday evening, was struggling with a light niggle. Van der Merwe's call-up provides extra cover at loosehead prop.
The Springbok team: Zane Kirchner, JP Pietersen, Jaco Taute, Jean de Villiers (captain), Francois Hougaard, Pat Lambie, Ruan Pienaar, Duane Vermeulen, Willem Alberts, Francois Louw, Juandré Kruger, Eben Etzebeth, Jannie du Plessis, Adriaan Strauss (vice-captain), Tendai Mtawarira.
Replacements: Schalk Brits, CJ van der Linde, Pat Cilliers, Flip van der Merwe, Marcell Coetzee, Morné Steyn, Juan de Jongh, Lwazi Mvovo. – Sapa