Lawn Tennis Association chief executive Roger Draper has admitted that British tennis is not likely to have five players in the top 100 until 2010.
Two years ago, LTA president Stuart Smith said Britain should have five top 100 players by the end of 2008.
But Draper told BBC Radio 5 Live's Sportsweek: "They were the wrong targets in the first place.
"Those were the targets set in the old strategy. By 2010 we can get five players in the top 100."
Draper insisted he had never been working to the target of getting five players into the top 100 this year - currently only Andy Murray and Anne Keothavong are in the top 100 and, on the men's side, Murray is the only player in the top 200.
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"You can track where the players are coming from," Draper said. "You can track over the next 10 years who is going to be in top 300, top 100 and so on and it takes time for those to come through.
"We have 11 boys in the main draw of juniors, but they are now going to go into an abyss for a few years as they go into the senior game.
"Our aim is to grow the game and create an environment where the winners can come through. The big emphasis is now on getting into schools and parks and getting people involved.
We have to make sure some of our youngsters who have got real desire and hunger to succeed at the very top end come through
"It comes back to competition. We have four million people playing in this country, but it isn't competitive enough. If you're not competing at eight, nine or 10 you don't learnt to win."
Asked about the success of other nations including Spain and Serbia who have several players in the top 50, Draper claimed Britain's relative lack of success could be partly explained by a lack of desire among some players.
"It's desire and hunger," Draper added. "When we say at age 10 that you have to give up school and you'll be travelling round the world for three or four months a year with no guarantee you're going to make it (as a professional), that decision is much easier if you are in Slovakia or Croatia.
"The reason Andy, Tim (Henman) and Greg (Rusedski) were successful is that they had tremendous parental support and ultimately it was down to the hard work they put in."
Draper also defended head coach Paul Annacone and Brad Gilbert, though he confirmed that Gilbert, who was initially brought in to work with Murray, will not be replaced when his contract expires.
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