Tottenham manager Mauricio Pochettino says closing the English transfer window early is "a massive mistake" and hopes "we fix the problem for the next season".
Pochettino is still sweating over the future of Christian Eriksen, who has 12 months to run on his contract, with the Denmark midfielder said to be keen on a move to Spain.
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If a European club makes a late bid for Eriksen - a reported target for Real Madrid - before their September 2 deadline, Spurs may be forced to cash in but will be unable to sign a replacement until January, as the window closed for English clubs on August 8.
"I wasn't in agreement [with the decision] but at that moment they believed that was best for the clubs," said the Spurs manager.
"But I think he [Tottenham chairman Daniel Levy] and a lot of people now realise it was a massive mistake. I hope that we fix the problem for the next season.
"We need to go back and operate in the same way that they operate in Europe because I think it's massive when you go to compete in the Europa League or Champions League.
"Champions League teams can create a problem for a team like us and it's so clear that I cannot be happy as a coach that in the last three weeks clubs from Europe can unsettle your team.
"For me it's not common sense and we need to go back quick, hope they have a good conversation at the Premier League and go back quickly [to how it was]."
Manchester United could also suffer from the change of transfer window with Paul Pogba and Alexis Sanchez attracting interest from European clubs.
Real have been linked with Pogba all summer, while Inter Milan are making a late push for Sanchez to bolster their forward line after Edin Dzeko committed his future to Roma.