Former world No. 1 Roger Federer believes the current dearth of top-level American players is bad for tennis.
For the first time since the rankings were introduced, no American is among the world's top 10 in the men's or women's lists.
Federer, however, believes the United States is merely suffering from a general lack of emerging talent that also can be seen elsewhere.
"There are not that many teenagers in the top 100, so I think many countries are going through a phase where they do not have the talent they hoped to have," said the Swiss, who is ranked third in the world.
"Even in France, Germany, England or America, all those countries are struggling and waiting for an up-and-coming player like we always hope for like Rafa [Nadal], Novak [Djokovic] and myself, or [Andy] Roddick or [Michael] Chang.
"This is kind of missing at the moment and those countries have to be patient, and this creates a lot of pressure on the people working in the federations and the media, especially in the bigger countries like America.
"It's going to be interesting to see how they get through it, and I hope they are able to come along with some more big players — especially for the States.
"I hope they get through it, because it's very important for the States to have big players."
He added, "In the women's game, I think we are all aware that if they wanted to or if they could play physically then [the Williams sisters] would be in the top 10 without any problems.
"It's worse on the men's side with just a few outsiders, but it's a fact that it's the first time in history this has happened."
