Of course, with just two caps to his name, the nippy van den Berg is just starting out his international career. But the Lions star gets a chance to stake his claim for the Bok No.9 jersey against the Barbarians in Cape Town on Saturday and Erasmus is his biggest fan.
"He is such a hard worker and such a particular guy in the way he wants to get things right," the Bok boss told the press this week.
"Morne reminds me a lot of Aaron Smith. I don't know if that's a good or a bad thing, but Aaron Smith was a great No.9. He is exceptionally fit. He was one of the guys who did the best in the fitness test."
"We had to nominate a few URC players of the year, and it always goes to the teams that wins, but one of my nominations was Krappies.
"I think he is a tidy and sharp player, but he only has two Test matches, and the one was in the rain against Australia. Hopefully, Cape Town gives him a better chance this weekend."
Despite featuring in a struggling Lions outfit, van den Berg managed to attract the attention of selectors. Erasmus added that intersquad competition is important and the more experienced Cobus Reinach - who is on the bench for Saturday - and Faf de Klerk need to be kept on their toes.
"The Lions team didn't do too well this season, so you couldn't judge him just by results," continued Rassie.
"But his output, what he tried, how he kept on fighting, and how well he understands what we want to do - I think that puts some nice pressure on the older guys like Faf and Cobus to keep grinding."
Erasmus also gave an update on Grant Williams' neck injury, which has kept him on the sidelines for the last two months.
"Grant will be ready for the second Test match against Italy," he said.
"This match we'll see Morne and Cobus, and the next game could feature one of the two - maybe with Faf starting or possibly on the bench, and then in the third, maybe Grant."