Brendan Guilfoyle, a football expert at P&A Partnership, said the headache for Spurs will not just be about balancing the books.
"In terms of the effect financially, Spurs is a well-run club but revenues will inevitably be lower so they will have to adjust that in terms of the wages they can offer and the transfer fees they can pay and still remain in the black," he said.
"The perhaps more immediate worry for fans, and I am a Tottenham fan myself, is that in terms of signing top players we won't be as attractive as we cannot promise the highest level of club football any more.
"There is also the worry that some of those star players, having tasted the Champions League already, will want to do so again and look to move elsewhere."
Spurs finished fourth in the Barclays Premier League, which would normally guarantee a place in the qualifying rounds of the Champions League, but they lose out because Chelsea take that fourth English place as European title holders.
Tottenham will earn only around ?5m in media rights from the Europa League instead of a guaranteed ?25m from the Champions League. There is also a significant loss in associated matchday, merchandise and sponsorship income that could see a further cost to the club of around ?10million.
Even more concerning for fans is the possibility of star players such as Luka Modric and Gareth Bale pushing for a move to clubs that are in the Champions League next season.
Spurs fans have reacted furiously to missing out on Europe's elite club tournament but UEFA say their competition rules, brought in after Liverpool won the competition but finished outside the top four in the Premier League, are clear.
Tottenham earned 31.1m euros (?25.1m) in TV money and bonuses from their 2010/11 season in the Champions League. An English club making the Europa League quarter-finals earns a total of 6m euros (?5m).
Source: PA
Source: PA