The Stormers star, who represented South Africa in 10 Tests and was part of the Boks' 2019 Rugby World Cup-winning squad, will realise a dream when makes his first appearance for the famous invitational side.
He will form part of a powerful Barbarians line-up which includes the likes of All Blacks legend TJ Perenara, Fiji and ex-France star Virimi Vakatawa, Scotland wing Duhan van der Merwe, Wallabies flyer Andrew Kellaway and England prop Kyle Sinckler.
The encounter will be a full circle moment for Gelant for various reasons as apart from taking on his Stormers and Springboks teammates, he will also be reunited with South African-born Van der Merwe.
They attended Outeniqua High School in George before moving to the Blue Bulls but they went their separate ways in the professional game when the latter left the Pretoria-based outfit to further his career in Europe before eventually representing Scotland at Test level.
Gelant is looking forward to making his Baa-baas bow in Saturday's eagerly anticipated clash.
"It's special. It's every player's dream to play in a Barbarians team, playing with guys you play against or see on TV," he told the Barbarians' official website.
"The Barbarians is about implementing the fundamentals of the game, getting that enjoyment back and doing all the things that made you fall in love with the game.
"It's about having fun and getting to know world class players from all over the world.
"I know Virimi Vakatawa from Racing but we also played against each other in Sevens and then obviously South Africa vs France.
"I played with Duhan in school and to come here together more than 10 years later is amazing.
"We went to the Bulls from school but he was in the Sevens for a stint. I thought maybe we would get a chance to play together but we never got it. He's obviously playing for Scotland now so the dream was down the drain but then I saw he was also coming here. It's special."
The 31-year-old knows that a tough challenge awaits the Barbarians against the Boks but with lots of star power and experience in the Baa-baas' line-up for Saturday's showdown, combined with a competitive edge and a healthy respect for the world champions, he expects an enthralling encounter.
"It's going to be a nice occasion. It's against my teammates and guys that I know well," he added.
"They are the best in the world so going up against them is going to be a big challenge for all of us. It's not often that you can play against the world champs if you are South African.
"But they have special players with great coaches who are taking them to the next level. There is no average player at the Springboks and they are all together, which makes it even more difficult given we come together from all over the world.
"(The Barbarians is about enjoyment) but it's not necessarily going all out and not taking responsibility for what you do. We want to give our best punches that we put together and test them just as much as they are going to test us.
"We have guys that have pride in themselves, that have played at the highest level for a long time. Guys like Duhan, TJ Perenara, Andrew Kellaway. These are top professionals, they want to perform and with the respect we have for the Springboks, we want to go out and give them a good challenge.
"The game will require always three things (in attack). It's running, passing or kicking. It's just what do you want to do in a given moment and do you have enough responsibility with the decision you're going to make. It's a great place to look for space, see space and go to it with whatever necessary means."
"We just focus on the way we want to play rugby and we want to express ourselves in a way that's aligned with the Barbarians. It's my first time, so I want to make it memorable."
Apart from an exciting line-up, the Baa-baas also boast a star-studded coaching ticket headed by Argentina boss and former All Blacks head coach Scott Robertson.
Gelant is enjoying his time with the aforementioned duo, who are working alongside Racing 92 head coach Patrice Collazo and Los Pumas assistant coach Kenny Lynn with the Barbarians.
"Felipe is player that I used to watch. He's one of a few Argentinians that you could relate to in the way he played the game at 10 and 12, the way he controlled the game. His kicking game, passing game, he's running game," he added.
"Razor (Robertson) also, he is open, he is so down to earth and makes himself so accessible. You learn open-fire ideas when you are on the road. You share ideas and that's something I can take back myself but also to the Stormers and the younger guys.
"It's IP you can share with the world. It's so special."