Fifa insiders accept that questions will be asked about ?¨the home nations' future participation as independent countries if Scotland vote to remain part of the UK.
There has been continuing resentment about the home nations' special status within ?¨the body, which allows them to compete as separate nations in international football competitions while remaining a single political state.
All four also have key parts to play within Fifa as long-standing guardians of the laws of international football.
For historic reasons, the quartet represent half of the International FA Board (Ifab), the game's law-making body, with Fifa making up the other half.
There is also resentment over Britain's claim to the post of Fifa vice-president, established since it joined Fifa in 1946 and organised a Britain v Rest of Europe match in front of 130,000 spectators at Hampden Park. That raised £35,000 to get the world governing body back on its feet after the Second World War.
Fifa members such as Argentina's Julio Grondona and Trinidad's Jack Warner have made little secret of their opposition to such special privileges.
Referring to the continuation of special status after a No vote, a Fifa source said: "We understand it would come up as a conversation. It will depend on what comes to Fifa in an official capacity. It has been debated in the past without much happening."
However, the source did not feel there was a growing number of Fifa members objecting to the UK's special status.
Several non-British member associations have been wanting to scrap the Ifab in its current guise, believing that altering and adding to the laws of the game should be the responsibility of more than just four associations based on history and tradition.
In January, Fifa crucially announced that the composition of Ifab would remain unchanged.
The Fifa source added: "The special status of the British associations was debated as ?¨part of the Ifab reform which happened over the past couple of years and it was decided the guardians of the rules of the game, should be the four British associations plus Fifa.
"Members were part of the consultation process. There is an argument to negate that sweeping statement that a growing number of Fifa members object to that special status."
Scotland, Northern Ireland and Wales have made it clear ?¨they did not want their players ?¨to participate in a Team GB Olympic football side for London 2012. Their argument was that involving them at the games could jeopardise their independent status with Fifa.
But Fifa president Sepp Blatter has tried to assuage their fears, previously promising that the home nations' independence would not be compromised by a joint GB team.
A separate Fifa insider ?¨added: "If Scotland votes No ?¨then you're going to see that debate erupt again. There is going to be real pressure to ?¨have that UK disparity finally dealt with.
"In the wake of a No vote ?¨many of the countries envious ?¨of the UK's special footballing status would see this as a perfect opportunity."
A Fifa spokeswoman said the organisation could not comment on "potential future scenarios".
But she added: "For general information about Fifa membership, check the Fifa statutes that state 'each of the four British associations is recognised as a separate member of Fifa'. Currently we do not anticipate any changes to this provision."
Hamish Husband, of the Association of Tartan Army Clubs said: "If we vote No ?¨then there will be many repercussions, of which football is the least important.
"If by voting No it endangered the Scottish football team, I would just have to live with it. Hell mend us.
"If there was to be a British team, it affects England every bit as much as us, and since they have a bigger chance of winning the World Cup than us, then ?¨they should be more affected than us. And we should stand up for England's right to win the World Cup.
"If a guy decides to vote Yes to keep a Scottish football team, then, I am sorry, there's got to be more reasons than that."