They know it. Pete Sampras and Martina Hingis, the top tennis players in the world, can feel the rumble under their sneakers. It's a threat to their dominance that both acknowledged before the start this week of the Australian Open, the year's first Grand Slam tournament.
"It's going to be a great year in that so many new players are coming up," Hingis told reporters after her loss to Venus Williams in the Sydney International last week. "And you can't forget the old ones."
Right on the mark.
The formidable former No. 1, Steffi Graf, is planning a return to tennis next month after having spent most of last year on the mend. Among men, perennial contenders Yevgeny Kafelnikov, Goran Ivanisevic, and Michael Chang have the experience and the expertise to make a difference.
But Sampras and Hingis, tennis experts say, stand on a turf being rocked by the past, the present, and especially the future - players who rose from obscurity to prominence last year, such as Gustavo Kuerten, Patrick Rafter, Jonas Bjorkman, Venus and Serena Williams, and Anna Kournikova.
"This year will be an exciting year for tennis," says former US Davis Cup player Eliot Teltscher, who was appointed a national coach last week. "The game has depth."
Here's the big picture: In the past five years, 3,167 players have held an ATP ranking at some point. That's a lot of activity. In a rare occurrence last year, five newcomers jumped to the year-end Top 10. Among them Rafter went from No. 62 to No. 2, Bjorkman from No. 69 to No. 4, and Greg Rusedski from No. 48 to No. 6.
"[Today] guys ranked 20 and 30 have a legitimate shot at winning a major tournament," says Teltscher, who was once ranked in the Top 10. "The game's changed. When I was playing [in the 1980s] that was not [the case]."
Ponder this: Lleyton Hewitt, ranked 550 in the world, won the Australian Men's Hardcourt Championships earlier this month. The previous lowest-ranked player to win an ATP Tour event was Senegal's Yahiya Doumbia, who won in Lyon, France, in 1988 while ranked 453.
Not surprisingly, Hewitt instantly decided to drop out of school and pursue tennis full time. The Australian whose ATP ranking soared to 162, is the latest example of up and coming players.
Hingis faces a similar challenge. A group of teenage contenders are nipping at her heels. The Swiss teenager had a sensational season last year. She won 75 out of 80 matches and captured 12 titles.
But this year started differently. She lost in the first round to Venus Williams in Sydney. Many predict that Williams, her sister, Serena, Russian Anna Kournikova, and Mirjana Lucic of Croatia will battle it out with Hingis for the No. 1 spot over the next decade. Serena, who beat Lindsay Davenport in the same tournament, is being referred to as the more talented of the sisters.
Kournikova, who has trained in Florida, recently hired Pavel Slozil, Steffi Graf's first coach. The Russian teenager told the Australian media last week that the Women's Tennis Association (WTA) age-limit rule, which restricts the number of tournaments a player can enter until age 17, is a limitation in developing her skills. The age restriction for Kournikova ends on her birthday, June 7.
While hailing this fresh talent as good for the sport, US tennis officials are also expressing concerns.
The upheaval has led to a continental shift. The dominance of Americans has eroded while Europeans and Australians have gained. "Germany, Spain, and other federations are making a conscious effort so they can have the best players in the world," says Teltscher.
US hopes will continue to ride on Sampras's shoulders, Teltscher says.
For five straight years Sampras has held his ground. He became the only player in the Open era besides Jimmy Connors to finish No. 1 for five consecutive years.
Now Sampras is chasing history. He needs wins in three majors to break Roy Emerson's record of 12 Grand Slam titles and one to tie for the 11 held by both Bjorn Borg and Rod Laver.