Gerhard Aigner talks to Alan Green

2004 is the fiftieth anniversary of Uefa - the body which runs the richest and most influential part of the football world.

It's Chief Executive Gerhard Aigner retired at the end of last year, but before he did he spoke exclusively to World Football about the changes he has seen, and what he sees as the biggest issues affecting the game.

"We should insist that a player - if he wants to be a professional player - must pass a referee's test," he told me.

"How can a professional play football if not fully understanding of the rules and accepting the role of the referee? Players should pass a test and be a referee now and then."

He also warned against the policy of constructing a team using the 'shopping list' of a wealthy backer, as seen at Real Madrid in Spain and Chelsea in England.

"This team will hold together as long as the success is there" he said of Chelsea.

"It will fall apart if success is not there. You cannot put a team together by going out with a shopping list. A team has to be built if you want a long-lasting performance.

"Teams who have to defend the colours of a club in more difficult times are mostly constructed with players who have been growing up in the club or come from the region. This is a much better investment."

Aigner said shopping-list football was "a risky game, probably not very good for football".

Although Chelsea have a sizeable England contingent, Aigner also warned against the trend of recruiting too many foreigners.

"It doesn't make sense to have no English players in an English team" he told me.

"There must be a rule that says the English championship should be played by a majority of English players."