Gavin Thornbury has been drafted into the Ireland 'A squad for Friday's game against an All Blacks XV after Tom Ahern was ruled out with a shoulder injury.
Ulster duo Nathan Doak and Tom Stewart will also join the squad later this week, having both featured for Emerging Ireland during last month’s tour of South Africa.
Twelve players linked up with the Ireland squad on Sunday night including Jamie Osborne and Roman Salanoa, who were declared fit after completing return-to-play protocols.
Thornbury has made an impressive start to the season with Connacht, helping the Westerners end the first block of BKT United Rugby Championship fixtures with successive victories.
Ireland ‘A’ face an All Blacks XV that includes Damian McKenzie, TJ Perenara and Roger Tuivasa-Sheck at the RDS on Friday, with the senior side taking on world champions South Africa at the Aviva Stadium on Saturday.
The Springboks arrived in Dublin late on Sunday night after their flight from Johannesburg via Dubai was delayed by five hours.
Bulls pair Sbu Nkosi and Marco van Staden have remained in South Africa while they await the results of medical scans on rib injuries suffered in Sunday's URC win over the Sharks.
Cheslin Kolbe was due to link up with the squad on Monday after playing for Toulon in their Top 14 loss at Bordeaux-Begles on Sunday night.
"The entire squad with the exception of the injured players and Cheslin reported for duty in Dublin on Sunday night and despite a few changes to our programme, we have a full training day on Monday," said South Africa director of rugby Rassie Erasmus.
Ireland Squad – Bank of Ireland Nations Series 2022
Backs (16): Robert Baloucoune, Joey Carbery, Craig Casey, Ciaran Frawley, Jamison Gibson Park, Mack Hansen (Connacht), Robbie Henshaw, Hugo Keenan, Mickael Lowry, Conor Murray, Stuart McCloskey, Calvin Nash, Jimmy O'Brien, Garry Ringrose, Johnny Sexton (capt), Jacob Stockdale
Forwards (21): Ryan Baird, Finlay Bealham, Tadhg Beirne, Jack Conan, Gavin Coombes, Caelan Doris, Tadhg Furlong, Dave Heffernen, Cian Healy, Rob Herring, Jeremy Loughman, Joe McCarthy, Peter O'Mahony, Tom O'Toole, Andrew Porter, Cian Prendergast, James Ryan, Dan Sheehan, Nick Timoney, Kieran Treadwell, Josh van der Flier
Ireland 'A' panel (12): Diarmuid Barron, Caolin Blade, Jack Crowley, Shane Daly, Max Deegan, James Hume, Dave Kilcoyne, Marty Moore, Jamie Osborne, Scott Penny, Roman Salanoa, Gavin Thornbury
Follow a live blog on Ireland v South Africa on RTÉ.ie/sport and RTÉ News app this Saturday from 5pm with live radio commentary on RTÉ Radio 1
