Carling, speaking on behalf of senior players, stressed that the England team must come first in the club versus country argument and he viewed next season's fixture list with great concern.
A member of a successful team who are committed to 22 league matches and possibly 10 more in European Cup and Pilkington Cup tournaments could reach 40 matches per season, with his international commitments added in. Carling pointed out the clubs are in danger of making demands on their main players that will detract from the health of the national game.
"There is genuine worry that the clubs' commercial aspirations have driven them to demand a level of competition which will neither improve the all- important standards of play or is in the interests in the financial health of the game," he said. "The long-term prosperity of English rugby will be secured at international level. England must compete and win at world level. The clubs must take this on board.
"We have examples of problems in other sports where clubs control the players and play them too frequently at an inferior quality level, so that when players take the international stage they are neither adequately prepared nor as sharp as they might like to be."
He said that could disillusion young players who develop their enthusiasm for the sport from watching the national side.
"The players are worried that the clubs, in their short-term rush to success, will overlook the long-term ambitions and will saturate the market with matches, and possibly TV coverage, which could lead to general boredom."