Some of Europe's best young soccer players could be kept out of the 2012 London Olympics under a proposal by their clubs.

The European Club Association wants an agreement that players who go to the 2012 European Championship co-hosted by Poland and Ukraine won't be picked for the London Games, which kick off one month later.

Europe will have four teams in London: a British host team and three qualifiers from the eight-nation European Under-21 Championship, to be held at Denmark in June.

The 16-nation Olympic tournament has an age limit of 23, with teams allowed to pick three overage "wild card" players.