European football's governing body has delivered a damning verdict after an 11-month investigation into City Football Group's operations that was sparked by revelations of foul play from German news magazine Der Spiegel in November 2018.
The English champions have been found guilty of seriously breaching UEFA regulations by overstating their sponsorship deals in order to meet a requirement to break even or spend within their means.
City are also risking a points deduction in the Premier League this season due to pressure from UEFA.
England will still get four places in the next two Champions League competitions so fifth place in the Premier League will now mean a lot more than the consolation prize of a place in the UEFA Europa League.
The club was also fined an equivalent of $48 million but that is the least of its worries.
City have denied any wrongdoing and have said they will appeal the sentence.
Should they fail to reverse the ban to play in the Champions League, serious questions will be asked if this is the end of the Abu Dhabi-backed super club as we know it.
City need Champions League football and its obscene revenues every year to subsidise their massive payroll.
Kevin De Bruyne, whose six-year contract expires in 2024, reportedly earns $680,000 a week, Raheem Sterling $582,000 and Sergio Aguero $447,000.
Two years out of Europe's lucrative tournament is a long time for a club of City's size and it could take them years to recover from this debacle while at the same time adhering to UEFA's strict financial regulations.
Assuming City would still afford or be prepared to keep their costly stars, how many of them would be inclined to stick around knowing that they would not be able to parade their extraordinary skills on the biggest stage of all.
Any good player would feel privileged to play in England but being part of the premiership without the carrot of Champions League football is like visiting the Louvre and not being allowed to see the Mona Lisa.
The sanction is also expected to affect the future of highly respected manager Pep Guardiola.
The man who lives for the Champions League, which is where he made his name as a master mentor with Barcelona, will more than likely leave the club and renew his liaison with the tournament somewhere else.
Which is probably all the motivation he needs to make a last-ditch attempt to win this year's competition for the first time in the club's history.
In the knockout phase that kicks off on Wednesday City face Spanish masters Real Madrid in the tie of the round of 16.
You also wonder if, as the parent company of several foreign clubs including Melbourne City, Yokohama F. Marinos and New York City, CFG will now sever its ties abroad or cut back its operations?
These clubs would be entitled to feel rather nervous about their status as the full meaning of the ban on City becomes more clear.
One thing is certain, though. By standing firm against such a powerful force as Manchester City, UEFA have drawn a line in the sand in a brave bid to salvage what's left of club football's integrity.
The game is not in a good place as far as money and greed are concerned and there's a long way to go yet to clean it up but, hey, it's a start.
