WIMBLEDON, England (AP) — Rafael Nadal has helped his nation cure its longtime aversion to lawn tennis, and he'll be one of three Spanish men playing Monday in the fourth round at Wimbledon.

Switzerland, France, Russia and Croatia have two players apiece among the final 16. Britain, which last won the men's singles title in 1936, advanced one man to the second week, as did Australia, Germany, Serbia and even the island of Cyprus. And the United States? None.

The nation that produced Andre Agassi, Don Budge, Jimmy Connors, John McEnroe, Pete Sampras and Bill Tilden finds itself in a collective slump. And there's no sign of a turnaround.

"We've been struggling for a long time, and it has just gotten worse," said Gene Mayer, a former top-five player who coaches privately in New York. "We just are producing no players."

Tennis finds itself in a vicious cycle. With fewer Americans doing well, the sport becomes less popular in the United States, and participation drops.