The coronavirus pandemic will cost Europe's 20 richest football clubs over £1.7bn by the end of this season.
The Deloitte Football Money League survey found the clubs had already lost around £976m up to the end of the extended 2019-20 season.
Clubs have suffered considerable losses on both broadcast and matchday revenue.
Barcelona generated more money than any other club in Europe, but still had the second-largest revenue fall in absolute terms.
The Catalan club saw a drop from £741.1m to £627.1m but remain narrowly ahead of La Liga rivals Real Madrid, whose revenue fell from £667.5m to £627m.
Bayern Munich (£556.1m), Manchester United (£509m) and Liverpool (£489.9m) make up the top five with Liverpool moving up from seventh last year, replacing Paris St-Germain.
Manchester City, Chelsea, Tottenham Hotspur and Juventus make up the remainder of the top 10.
Eighteen of the 20 clubs retain their places from last year's survey - with Zenit St Petersburg (15th - £207.4m) and Eintracht Frankfurt (20th - £152.6) replacing AS Roma and West Ham United.