The Springboks have released four squad members to the SA 'A' side for the first of their two matches match against the England Saxons in Bloemfontein on Friday.
Hooker Scarra Ntubeni, flank Sikhumbuzo Notshe, scrum-half Nic Groom and fly-half Garth April are all members of the 31 Bok training squad that first got together last week in Stellenbosch.
They will join coach Johan Ackermann and his SA 'A' side on Tuesday evening in Bloemfontein and will be in action on Friday.
The four players will rejoin the Springbok squad on Saturday in Cape Town, where the Boks are facing Ireland in the opening Test of the Castle Lager Incoming Series.
Meanwhile the Springboks continued with their final preparations for the weekend’s big clash with a split session between backs and forwards in Cape Town on Tuesday.
The backs were put through their paces at the Cape Town Stadium, while the forwards performed their drills at the Green Point Track next door.
Experienced Springbok number eight Duane Vermeulen said afterwards it was great to be back in South Africa.
The Toulon loose forward is one of only three overseas-based players in the Bok squad.
"It is very nice to be back amongst team mates, those I know and also to meet the new faces," Vermeulen said in an official SA Rugby release.
"There is a great spirit in the camp and we all looking forward to the first Test on Saturday.
"The Irish will come with a huge onslaught and our job this week is to make sure we prepare ourselves thoroughly so we are able to meet that challenge."
Springbok coach Allister Coetzee will name his matchday squad on Thursday.
The last time the Springboks and Ireland met in a Test on South African soil was 12 years ago, when Coetzee was one of the assistant coaches.