The Daily Mail reported today that South Africa are in negoiations to make the Six Nations the Seven Nations following the 2023 World Cup.
The move would see the Springboks leave the Rugby Championship to join the northern hemisphere tournament in 2024.
"This proposal, the ramifications are disastrous for Australia and New Zealand," said Matt Williams on Virgin Media's coverage of the Six Nations on Saturday afternoon.
"How it would pan out with their provincial sides in rugby below this is hugely questionable. When you bring in people who are looking for short-term return on bucks, this is what you get. There's so much that is wrong with that proposal for the game.
"Personally, I think it would be an absolute disaster for the game, in the world. In the north, they will make a lot of money but the game will die in Australia.
"It will smash the game in New Zealand because they can't get income, it will be cast aside. Below this, they can't generate the money to run the game. If you take the South Africans out of the south, it's going to cause a train smash down there."
Shane Horgan believes that the move would not be about growing the game.
"It's not about redressing the balance and the inequities that are in the world game but it is about generating a lot more money for the Six Nations and indeed South Africa," said Horgan.
If you looked at it with a myopic view, it's going to generate big interest and big money, and increase the televisions deals over here. By including South Africa, there will be more interest worldwide but there are more challenges.
"We've got a Five Nations that became a Six Nations, that has huge interest all around the world - it's a fantastic tournament," added Ronan O'Gara.
"It doesn't become a Seven Nations, it becomes something different. If it ain't broke, don't fix it. The Six Nations works brilliantly."
— Virgin Media Sport (@VMSportIE) February 8, 2020