MADRID - ATP chief Mark Miles is confident there will be no shortage of appeal in men's tennis even after Americans Pete Sampras and Andre Agassi retire.

Sampras, 31, is considering his future in the sport after winning his 14th grand slam title at the U.S. Open this season.

Agassi, arguably the most popular player in the sport, is still going strong at the age of 32 but inevitably his remaining time at the top is limited.

Miles, speaking in the Spanish capital on the opening day of the Madrid Masters, shrugged off suggestions that there were no players with the same sort of charisma to replace them.

"First of all, I don't think Mr. Agassi would want it talking about his retirement," Miles said.

"He's working as hard as ever this season and he's had superb results. I think he's physically and mentally prepared to play tennis at the highest level for some time to come.

"I remember, though, that back when John McEnroe and Jimmy Connors were about finished people were asking the same question, just changing the names.

"The thing that's always happened in tennis, and I'm completely confident it will happen again, is that out of nowhere stars are born."

Miles mentioned young Americans Andy Roddick and James Blake as future favorites, saying they had won over French supporters during the recent Davis Cup between the two countries in Paris.

"The French fans responded to those players as if they were their own," Miles said.

"The same is true for many players. Juan Carlos Ferrero is a great athlete, has an artistic type of game and is a very sympathetic personality.

"Carlos Moya has been a sex symbol for a long time and I think Lleyton Hewitt is going to be a champion for many, many years."