New UEFA president Michel Platini has been warned by fellow Frenchman Arsene Wenger that he may not be able to deliver on his ambitions to change the Champions League.
Platini, who won yesterday's presidential election to oust Lennart Johansson from European football's top job, will present proposals in April which aim to eventually limit the number of clubs in Europe's elite competition to three from any one country.
Wenger said: 'I am scared that he based his programme on something that he will not be able to deliver because he cannot decide that - that has to be voted [by UEFA's executive committee].
'I am surprised when people say `yes that's what he promised' but he cannot deliver that. It can only be delivered if it is voted.
'If it gets voted, we will all adapt and fight harder to be number three but I do not think it will change the destiny of the game.'
Wenger, who worked under Platini's father at Ligue 1 club Nancy, believes the proposed changes helped him win the vote among UEFA countries by 27 to 23.
He added: 'I'm not surprised - the three big countries will vote against you, they will vote for Johansson.
'But you get Andorra, Serbia and the rest and that's the best calculation he made.
'I know him very, very well and I like him as a person. He is a very intelligent person, he loves football and I've known Platini for 30 years.
'His father was influential on my career and had a big influence on his son as well.'
Manchester United manager Sir Alex Ferguson also spoke out against changing the current Champions league set-up.
Ferguson said: 'The only way you could get rid of the fourth team is by reducing the competition or bringing in more teams from other countries.
'The way it is at the moment, with the top countries entering their top teams, you get some fantastic games.
'It is a fantastic tournament and you are playing all the best teams. I don't think a lot needs to be done to it.'
The Football Association and Premier League are expected to try and persuade Platini to maintain the status quo which allows England, Spain and Italy to have four teams qualify for Europe's premier club competition.
Platini said: 'The new format of the Champions League is for 2009.
'I talked about finding a better equilibrium for the number of clubs and that's for 2009-10.
'The final decision will be in April so we have a few months still to see which way we will go, but I would like a better equilibrium - it is very close to my heart.
'If you are just talking about one club in England that doesn't convince me that it is not the right thing to do.'
The 51-year-old will serve for the next four years and will also replace 77-year-old Johansson as a FIFA vice-president. Platini immediately invited Johansson to become an honorary president of UEFA.
The former France captain and coach said: 'This is just the beginning of an adventure.
'I'm happy today to be able to represent European football. I'm very moved and very happy.
'When I was a footballer, when you won a great victory you received a cup and went on a lap of honour. This is a great victory for me but I'm not going to do a lap of honour because the now the work starts.'
The election victory followed a tense campaign which descended into bitterness in the days leading up to the vote.
In his final address to the 52 UEFA member associations, Johansson launch an angry attack at FIFA president Sepp Blatter, who had publicly backed Platini at the opening of the Congress yesterday.
Johansson said: 'I appreciate the FIFA president's words about what we have achieved in the 17 years of my presidency but I cannot appreciate it when the FIFA president interferes in an election process here in UEFA.
'It's not the FIFA president, it is you the Congress taking the decision.'
Platini has tried to appeal to the smaller countries and also supported a proposal by the Scottish FA for UEFA to carry out a feasibility study into expanding the European Championships finals to 24 teams.
Johansson's age has not helped his cause, especially with UEFA having a rule that committee members must retire at the age of 70.