The coronavirus pandemic will end up costing Europe's top clubs around two billion euros, according to forecasts from Deloitte.
The finance firm's annual Football Money League shows that the top 20 revenue-generating clubs lost around 1.1bn euros (£975million) during the 2019-20 season due to factors including the lack of spectators and effect on broadcast income.
Some of the latter will be made up in the 2020-21 accounts, along with deferred prize money for many clubs, but the ongoing effects of the virus see the drop in revenue projected to reach 2bn euros (£1.75bn) between the 20 clubs.
Tim Bridge of Deloitte's Sports Business Group told the PA news agency: "We usually release our money league and talk about the growth in revenue but of course football is not immune to the Covid-19 pandemic.
"The revenue that's been missed out on is driven by the lack of fans in the stadium, the lack of interaction on a matchday – fans spending in the club shop and buying food and drink – and there is an element that relates to revenue that broadcasters have either clawed back (or deferred) to next year.
"There is an element of the 19-20 season being played in the 20-21 financial year, so there's a rollover of a certain element of revenue, but for this season the matchday revenue is the most significant hit for the clubs.
"The commercial revenue has so far held up. I think many people were concerned that in the short term there would be an immediate shock from sponsors pulling out or unable to pay their bills but at the moment these biggest clubs have been able to hold up their commercial value."
That commercial performance helps Real Madrid close within £100,000 behind Barcelona, who suffered a 15 per cent drop in revenue to £627.1m (715.1m euros), as the rival clubs retained the top two places in the Money League.
Manchester United are the highest-ranked of seven Premier League clubs in the top 20 but have fallen behind Champions League winners Bayern Munich to fourth place on £509m, down 19 per cent or £118.1m on the 2018-19 season.
Bridge added: "In Germany they managed to complete the season prior to the end of June so the vast majority of revenue was recognised within the correct financial year.
"That has contributed but of course on-pitch Bayern Munich had a fantastic season, competing in the Champions League compared to Manchester United who were competing in the Europa League, so there would likely have been a closing of that gap anyway."
THE TREBLE IS OURS 🏆🏆🏆 What a team!What a season! #MiaSanMia pic.twitter.com/34DjNlqoCt — FC Bayern English (@FCBayernEN) August 23, 2020
Liverpool and Manchester City rank fifth and sixth with Chelsea and Tottenham also in the top 10, Arsenal 11th and Everton 17th.
The Toffees were one of only two clubs in the top 20, along with newcomers Zenit St Petersburg, to actually post improved revenues compared to 12 months previously – but it is their neighbours across Stanley Park who Bridge expects to thrive in years to come.
He said: "A club such as Liverpool, who've made a concerted effort to engage with fans using digital and social media channels – that may well have created new revenue-generating opportunities and may mean they've gained a competitive advantage."
West Ham dropped out of the top 20 along with Roma – but it is clubs much further down the pecking order, in the lower leagues, who will suffer most from reduced incomes.
Bridge said: "Matchday revenue for these biggest clubs is their smallest proportion whereas the further down the system you go, the bigger that proportion is.
"The loss of fans is really felt most acutely by those clubs further down the system. That's why the support packages that have been talked about are absolutely essential to the future of these clubs."
