There is an interesting similarity between the trajectory of Rafael Nadal's and Justine Henin's Grand Slam careers. When the Spaniard first announced himself on the terre battue of Roland Garros as a 19-year-old, the Belgian was his claycourt counterpart in the women's game.
The two went on to reign supreme at the French Open for three years in a row, from 2005 to 2007. Every possible opponent who came in the way was crushed, as Nadal and Henin established their hegemony on the red dirt.
Rafael Nadal, however, was much more than just a claycourter. And he proved that when he edged Roger Federer in an epic five-setter on the lustrous lawns of Wimbledon in the summer of 2008. Many consider that to be the greatest tennis match ever played.
But Henin, who finished her career with seven glittering Slam trophies, had one glaring hole in her illustrious resume - she could never win Wimbledon. Henin never managed to complete the Career Slam, but the two-time SW19 runner-up knows better than anyone what a monumental effort it takes to master both clay and grass in the same year.
And that is why, when former World No. 1 Mats Wilander asked her thoughts on Nadal's 2008 Channel Slam win on Eurosport's Players' Cut, the seven-time Major winner couldn't stop praising the southpaw's colossal feat.
Rafael Nadal's focus in practice sessions stood out: Henin
Having observed his practice sessions from close quarters in Paris, the 2004 Olympic gold medalist singled out his focus and determination as the qualities that struck her. With fire in his eyes and intensity in his training, Nadal was really on a mission to prove himself on all surfaces, according to Henin.
"I will always remember one image coming from the French Open to Wimbledon," the Belgian said. "I don't really remember what year it was, but I saw Rafa on the practice courts over there, and, you know, hitting harder and more focused. Carlos (Moya) was talking about the focus, you can see it's in him.
"He reminds me also a lot (of myself) because sometimes he looks anxious, he has doubts but it looks like the hard work gives the confidence. And I could see in his eyes that there was a mission, also to really prove he was really good on other surfaces."
The former WTA World No. 1 then emphasized the magnitude of Nadal's French Open-Wimbledon double in 2008 by drawing comparisons with her own career. Henin herself won multiple Slams in a year twice; in 2003 and in 2007, she found success on the hardcourts of US Open in addition to bagging the French Open. And she understands better than anybody how difficult it is for a claycourter to adapt their game to other surfaces - and how much diligence and perseverance is needed to conquer it all.
The US Open comes more than two months after the French Open, so Henin got enough time to make all the necessary tweaks to her game ahead of the North American swing. But to take your clay game to the lightning fast grasscourts of SW19 in a matter of a few weeks, and still somehow find success there, is a different thing altogether.
For Nadal, there was another unique challenge. Roger Federer was the undisputed king of grass at that time, having won Wimbledon five times in a row from 2003-07. Notably, two of his final wins came over the young Spanish claycourt supremo.
It was never going to be easy, which is why Henin - and the rest of the world - continue to marvel at the magnitude of what Nadal achieved.
2008 Wimbledon win turned Nadal into a superstar: Wilander
Despite the two Wimbledon final losses, Nadal did not give up. He just motivated himself to rise to the occasion in 2008, and achieve the one that that everyone thought was impossible.
That's what stood out in particular for Henin, as she stated:
"When I won on hardcourt after the French Open, it was two months later at the US Open. For me to win in the United States, it was far from my culture. It was tough for me. But to win somewhere else in another kind of surface was something huge.
"So I'm pretty sure (it was important) for Rafa to prove that to the tennis world because everyone was just talking about his game on clay. And to prove that he could win on grass (was huge). It wasn't on hard, it was on grass. Yeah, I thought it was something really amazing.
Concurring with the Belgian, Wilander added that it was the Wimbledon win that truly made Rafael Nadal a superstar.
"I think that turned him into a superstar. I had never thought that with his style, he could (win Wimbledon)," said Wilander.