Sir Alex Ferguson believes a global Super League would not be attractive to leading English Premier League teams.
It has been reported the European Clubs' Association has suggested a dramatic shake-up of football's premier European club competition, which could see the Champions League group stage transformed into a 32-team division.
A final decision on any proposed new format would be taken by UEFA.
Such a plan may spark fear among some that it could lead to the creation of a European Super League, with the 32 clubs eventually split into two divisions and 16 home-and-away games.
FIFA, meanwhile, wants to extend the current Club World Cup format to some 24 sides from 2021 – a move which has brought strong opposition from the European governing body.
There have also been suggestions a global Super League could eventually be organised, which would see member clubs no longer play in domestic competitions.
However, Ferguson – who guided Manchester United to European success in 1999 and 2008 as well as some 13 Premier League titles – cannot understand the appeal.
"I struggle to see why an English team would need to leave," Ferguson told the BBC.
"Without question, it is money orientated, but surely this would not be attractive to our clubs in the Premier League, which at the moment is the best domestic league in world football and is well supported financially by Sky, BT and now Amazon.
"Furthermore, the attraction of playing in the Champions League is huge for players, coaches and fans alike, as it remains the ultimate test in club football.
"A lot of clubs with great history could be lost if their partners in the Premier League upped sticks.
"I strongly believe this is a realistic appraisal of the value of domestic football."
Under the new proposed schedule for the Champions League, each club would play 10 matches against 10 different opponents with the top-eight sides qualifying for the round of 16.
The remaining 16 teams would then take part in a two-legged play-off to join them in the knockout phase.
Home and away matches would be scrapped in the initial group stage and – according to the report – fixtures would be determined on the 32 qualifiers being divided into four pots based on their coefficient.
It is claimed that the top eight would also be guaranteed automatic qualification for the following season's Champions League.
The European Clubs' Association consists of 232 teams and was founded in 2008.
Manchester United, Chelsea, Arsenal, Liverpool, Manchester City, Tottenham, Everton, Leicester and Newcastle are among its members.
Juventus' Andrea Agnelli is the organisation's chairman.