LONDON—Rafael Nadal issued the warning a couple of weeks back. He said the generations in tennis don't last a generation, that before you know it, there's a new group of stars coming on—the way Nadal and Novak Djokovic and Roger Federer arrived seemingly moments ago.
The people we know, the champions, will take their leave, as champions inevitably do. Djokovic is only 27, Nadal 28, but they're looking over their shoulders. And playing as hard as they can against the guy across the net and that pest Father Time.
"Our generation is on the way out," Nadal told the media after his victory in the French Open last month.
"We have all been here for a long while. It's normal. A generation is walking away and others will replace us. It will not come overnight, but it will come."
The Wimbledon men's semifinal Friday offers more than a hint. Yes, half the players are the establishment, Roger Federer, the greatest Grand Slam winner of them all with 17 victories, seven at Wimbledon, and Novak Djokovic, with six Slams, one of them at the All England Lawn Tennis Championships.
Then there are the other guys, "Baby Fed," Gregor Dimitrov, 23, who in his first Slam semi takes on Djokovic, and Milos Raonic, also 23, who faces the great Federer a month ahead of Roger's 33rd birthday.
Who wins? Paul Gallico, a sportswriter-turned-novelist, once advised: "While the battle isn't always to the strong or the race to the swift, it's a good way to bet."
So you've got to favor Djokovic, the No. 1 seed, and Federer, the No. 4.
Yet Dimitrov upset the defending champ, the local hero, Andy Murray, in their quarterfinal. And Raonic, who was born in Montenegro but moved to Canada when he was three years old, shut down Nick Kyrgios after Kyrgios stunned Nadal.
One of these days or months, as Nadal the realist told us, the new kids on the block or the court will be holding the trophies and our attention. It's only a matter of time, but is now the time?
Dimitrov, from Bulgaria, is as famous, probably more so, from his relationships than his tennis. He dated Serena Williams, and was there a comment at the end of the relationship that Dimitrov was "the man with the black heart?" For certain, he's the man from the Black Sea.
Now Dimitrov's gal pal is another champ, Maria Sharapova. "Grigor is the best thing ever to happen to my life," Sharapova told ESPN in an interview. "He is so sweet and considerate, and because we both play tennis, he understands the life I live, because he’s living it too."
This week he's living it even better: Sharapova, who's won all of the four Grand Slams, was eliminated in the fourth round.
Dimitrov is the only male this year to win on all three surfaces used in tennis, the victory on grass coming a little more than two weeks ago at Queens, a Wimbledon warm-up.
Peter Lundgren, who coached Dimitrov as a teenager, called him "Baby Fed" because he said, at that early stage of his career, he was ahead of Federer. Dimitrov didn't like the label, which like most nicknames has a staying power beyond its shelf life. Now his coach is Australian former tennis player Roger Rasheed.
Dimitrov is quick and strong. And hungry, for a title that is.
"As one of the younger guys, I know that we strive for this," he said after the win over Murray—a win the British papers are describing as everything from bad play for Murray to a conspiracy.
"We want to prove ourselves," he said, "to show the big guys we're just around the corner."
Or more specifically, at the other end of the court.
At Indian Wells in March, Djokovic, Dimitrov's semifinal opponent here, crashed a press conference and joked: "My friend Grigor here, best-looking guy on the tour. You don't need to talk about your tennis too much. You've had so much success this year. Let's talk about your looks."
Raonic isn't worried about looks, just about looking. And planning.
"I'm not playing the seven-time Wimbledon champion,” was his head-in-the-sand comment about Federer.
"I’m playing a 32-year-old man. I'm playing a guy who's standing in the way of what I want to achieve.
"The goal is to be the best player in the world, and this is another step on the ladder."
A big step, certainly, but a step that if he wants to get to that goal must be taken, sooner rather than later.
Raonic, as his countrywoman, Eugenie Bouchard, becomes the first Canadian to reach a Wimbledon final, has that blend of toughness and confidence so needed in a sport where a competitor has no help when the action is underway.
"It's a thing, I guess that you can't really run time in one way," he said about the shift of those at the top.
"New guys got to come up, and they've got to step up. We've been doing better and better, especially throughout the year."
And now on the grand stage at Wimbledon, they have a chance to do their best.
Art Spander, an award-winning columnist, has covered more than 50 Grand Slams in his career. Unless otherwise noted, all quotes were obtained firsthand.