The Bulls have confirmed that three incumbent Springboks, Jan Serfontein, Handrč Pollard and Marcel van der Merwe will stay in Pretoria.
Serfontein (2017), Van der Merwe (2016) and Pollard (2017) all confirmed or extended their contracts with the Blue Bulls Company.
Van der Merwe made his international debut for the Springboks against Scotland last weekend.
"Marcel has a long and promising career on the highest level ahead of him and we are pretty pleased that he will be playing that in a Bulls and Blue Bulls jersey," said high performance manager Xander Janse van Rensburg.
Pollard started in his debut test match as well, a week after being named IRB Junior Player of the Year in New Zealand.
Pollard captained the Junior Springboks at the Junior World Championship in New Zealand and also become the top points' scorer of all time in the JWC competition at the event, where South Africa lost to England in the final.
Serfontein, also an IRB Junior Player of the Year winner in 2012, started at centre in the recent Castle Lager Incoming Series against Wales and Scotland.
He made his test debut in 2013 as a 20 year old and has played in 12 tests, scoring one try.
"Jan and Handrč have all the attributes to become legendary Springboks and there is little doubt that they will be very influential players for the Bulls and Blue Bulls for many years to come," added van Rensburg.
"Both committed to the Bulls as school boys already and it is fantastic to know they want to stay on, share and contribute to our vision of being the top team in the Super Rugby and Currie Cup competitions. Their loyalty and commitment to the Bulls are a fine example to others."
Janse van Rensburg also confirmed a number of players that confirmed or extended their contracts, amongst them a big group of 2014 Junior Springboks.
"The Under-20's impressed everyone with their performances in New Zealand this year and it is great to see how many of the stars in that team has committed themselves to continue their careers with us."
2014 Junior Springboks: Corniel Els (2016), Dayan van der Westhuizen (2015), Abongile Nonkontwana (2015), Nqoba Mxoli (2015), Nicholaas Janse van Rensburg (2016), JP Smith (2015), Warrick Gelant (2016), Jesse Kriel (2015), Daniel Kriel (2015), Pierre Schoeman (2016), Arno van Wyk (2015).