WIMBLEDON, England — 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."

For the first time since 1926, only one U.S. male — No. 102-ranked Bobby Reynolds — reached the third round at Wimbledon. He lost Friday.

The problem isn't grass. At last year's French Open, American men went 0-9, their worst showing on the Roland Garros clay in at least 40 years. The last U.S. male to win a major title was Andy Roddick at the U.S. Open in 2003.

The drought is less noticeable on the women's side only because of the Williams sisters, who have combined for 14 major titles. They and Bethanie Mattek were the lone Americans to survive the first week at Wimbledon.

American men went 5-12. Eight lost in the first round, including Olympians Sam Querrey and Robby Ginepri. Andy Roddick and James Blake lost in the second round.

Poor Reynolds, delighted to equal his best Grand Slam result at age 25, was left to explain why U.S. fortunes continue to decline.

"Around the world tennis is a huge sport, and maybe it's not No. 1 over in the States," he said. "In the States you have basketball, baseball, football, golf. You have so many avenues that people can try out. I think that might have something to do with it."

But tennis has always been well down the list of the most popular sports in the United States. What has changed is the way kids learn the game, with the most precocious youngsters often being steered at an early age toward a tennis academy.

Mayer said the grass-roots tutoring of earlier eras produced better results.

"It was quality coaches working in intimate settings with players," he said. "Now everyone goes to academies so young, and you never learn to play tennis. You don't learn at age 7, 8, 9, 10 in a group setting with 200 kids. You learn it one-on-one with a coach."

While development lags in the United States, waves of talented youngsters keep surfacing in Europe, Asia and South America. Ricardo Acuna, a national coach for the U.S. Tennis Association, said Americans are winning less because the game has gone more global.

"More than it's a drought, it's that the world got better," said Acuna, a Chilean who ranked in the top 50 in the mid-1980s.

"When I first started playing, 50 percent of the draw was Americans, and then there was the rest of us — South Americans or Europeans. But now it's the other way around, especially with like France and Spain, and then you have the smaller countries too that have a lot of good players.

"Tennis is the biggest sport or the second-best sport in those countries. In the U.S. it's probably like the 30th sport behind many others."

Tennis finds itself in a vicious cycle. With fewer Americans doing well, the sport becomes less popular in the United States and participation drops. That means fewer youngsters take up the game, which reduces the pool of potential future champions.

Three-time Grand Slam champion Lindsay Davenport has noticed a transformation of tennis during her career.

"It has kind of slipped in the rankings of sports watched on TV and overall popularity in the public," Davenport said. "I don't know exactly what the answers are to get it to be more popular, but worldwide it's definitely a bigger hit than in the United States."

In April, the USTA hired Davis Cup captain Patrick McEnroe to save American tennis. His job is to coordinate player development, with help from a new advisory board and coaches commission to scout and groom talent.

But past USTA pledges to improve development have gone unfulfilled, and even if McEnroe is successful, the payback is at least a decade away. It's certain there won't be any comeback by the U.S. men at this year's Wimbledon.