He has been interrogated daily here about the condition of his knee, his head and essentially his heart. Is this any way to treat the defending Australian Open champion?
With the scrambling Scotsman Andy Murray up next in the quarterfinals, the heat has been turned up on Nadal. Murray has not dropped a set so far, and there is a growing sentiment that he is poised to become the first British man to win a Grand Slam title since Fred Perry in 1936.
All Nadal can do is shrug.
"The numbers are the numbers, so probably it is not the best moment in my career against the top players," Nadal, seeded second, said. "You have some ups and downs in your career, but I am here to fight. Nobody can ask more of me. I try my best all the time. If I lose another time in two days, I will try in the next tournament."
Nadal, 23, has beaten Murray seven of the nine times they have played. They have met on some of tennis's big stages before, including a five-set thriller won by Nadal here in the fourth round in 2007.
In 2008, however, Murray beat Nadal in the semifinals of the United States Open in a match that took four sets over two days and two courts -- Louis Armstrong and Arthur Ashe Stadiums -- because of rain.
Murray, 22, has already gone further than ever at Melbourne Park, and his performance in a three-set sweep over the big-serving American John Isner on Sunday was close to flawless. Murray delivered 71 percent of his first serves and had only 9 unforced errors in a 7-6 (4), 6-3, 6-2 victory. The world's top player, Roger Federer, has hailed Murray's recent play and says he has matured into a Grand Slam contender.
Murray, too, says he is becoming more seasoned with each match and is in command of his game like never before.
"I've concentrated well in all of my matches -- that's really it," he said. "Not a whole lot in my game's changed. I guess it's a maturity thing. You learn to, I don't know, deal with the tight situations better, and your focus holds for longer.
"I'm playing well," he added. "No question about that. I just need to play like I have been, and maybe a bit more if I want to win the tournament."
Nadal has hardly played poorly here. He handled the big serve of the 6-foot-10 Ivo Karlovic, 6-4, 4-6, 6-4, 6-4, to reach the quarterfinals. Still, he has been scrutinized for signs that tendinitis may have crept back into his knee or doubt into his head after last year's second-half swoon.
Nadal insists, however, that he is on track to capture his seventh major title.
"You know, you have some up and downs in your career, and probably the last eight months or six months, I had more problems than usual with my knees, later with the abdominal," he said. "So the important thing is don't have losses against the players that you have to win. So I did very well that last eight months, too. I didn't have bad losses outside of top-10 players. So when you are there all the time, finally you win."