Why? Because dozens of developing world leaders are set to assemble in the South African business capital for what could be a landmark meeting of the BRICS bloc of nations.

This is the grouping of large and fast developing countries - currently comprising Brazil, Russia, India, China and South Africa - which held its first Summit in Russia in 2009, eight years after a Goldman Sachs economist invented the acronym.

The eagle-eyed among you will have noted that these five countries have between them hosted two of the last four Summer Olympic and Paralympic Games, two of the last four Winter Olympics and three of the last four FIFA World Cups.

However, the prime focus of the IOC’s attention is likely to concern future rather than past sports events.

Specifically, the BRICS Games which are expected to take place next June in Kazan, just a month ahead of the Paris 2024 Olympics.

Anything that emerges in Johannesburg relating to this hugely sensitive event is bound to be closely scrutinised in Lausanne - especially given that one of the prime preoccupations of this week’s forum is expected to be expansion.

Reports suggest that a move to invite several new countries to join the BRICS club is set to be debated.

More than 20 countries are said to be interested in joining.

These are thought to include Argentina, Saudi Arabia and Indonesia, as well as possibly Iran, Belarus, Venezuela and the United Arab Emirates.

They would be the first new members since South Africa was added to the original group of four in 2010.

Concern in the foreign ministries of the old world powers may focus on whether the BRICS - whose members already include the world’s two most populous countries - could emerge as a rival to the Group of Seven industrialised nations, consisting of the United States, Germany, France, the United Kingdom, Japan, Italy and Canada.

The IOC’s chief preoccupation is likely to be rather different.

As things stand, a BRICS Games slotted in just ahead of Paris 2024 would be far from ideal.

But if it only involved athletes from five countries, even if some of them habitually inhabit the upper reaches of the Olympic medal table, well, it could probably be regarded, at least in private, as an irritant, rather than anything more significant.

The event would scarcely even be noticed in the traditional Olympic centres of North America and Western Europe.

Should the number of competing nations spike upwards towards 20, perhaps even more, on the other hand, you might well be drawn to conclude that the exercise amounted to a serious challenge to the IOC’s authority.

Not that the number of BRICS members is expected to quadruple in one fell swoop, or anything like it.

But if the principle of a major expansion were agreed this week, perhaps an invitation to the Games could be viewed as a gesture of goodwill to aspiring members.

I would think the Russian leader Vladimir Putin’s attitude towards the number of countries invited to Kazan would be the more the merrier.

How could the IOC react to such a development?

It is hard to imagine them trying to ban anyone who competes in Kazan from Paris, however many countries end up sending representatives to the Tatarstan capital.

Yet if they just try to ignore the whole thing, it would underline Lausanne’s impotence in the face of rebel events, when such occasions are backed and/or devised by powerful Governments, as opposed to, say, the defunct Global Association of International Sports Federations (GAISF).

There has also been talk of a "BRICS Sports Charter" being drawn up, as well as of further BRICS events.

In other words, the challenge posed by BRICS sport might be more than a one-off, even if the Russian invasion of Ukraine, and the anguished debate over how Russian and Belarusian athletes ought to be treated by international sports bodies in light of it, almost certainly has a lot to do with why the challenge has flared up now.

One saving grace from the IOC’s perspective could well end up being that a grouping as diverse as the BRICS already is - let alone as it might become - will probably find it difficult to make common cause on all manner of fronts for very long.

But a world that increasingly resembles a collection of competing power blocs being played off against one another by the uncommitted is unlikely to be easily navigable by a body with the universalist aspirations of the IOC.

The big players in such a world may well regard sport - as Putin seems to - as a useful diplomatic and propaganda tool.

In this environment, the holy grail of true autonomy for international sport is likely to remain a pipedream.