Melbourne - Rafael Nadal's back injury may be, in his own words, "nothing serious," but it is at least a signal that the Spaniard's body is worth considering as a variable in his effort to continue making history.
"I have not tried too hard to see what it was," Nadal told reporters in Melbourne on Monday, before boarding his flight home to Spain.
"I am certain that it is nothing serious, because the feeling is similar to what I have had other times too, only quite a bit more aggressive."
And yet this was probably the most bizarre injury in the current world number one's career: a major muscle spasm in his back early in the second set of the Australian Open final he lost to Stanislas Wawrinka by 6-3, 6-2, 3-6, 6-3 on Sunday - precisely a final that was supposed to be historic.
It is unusual for an apparently minor physical problem, one that can be left behind in a matter of only a few days, to cause such damage to a star sportsman.
Hours ahead of that final, tennis icons like Rod Laver and Pete Sampras were standing before the players' lounge, discussing history and the future, Nadal and his limits.
"In order to be successful, you have to be free of injuries, that's important," Laver prophetically told dpa ahead of the Australian Open final.
"I am lucky to have been able to do what I did without injuries," he said. Laver won the Grand Slam - the set of the four majors, all in one year - twice, in 1962 and 1969.
Sampras won 14 Grand Slam tournaments, precisely a number Nadal was hoping to match on Sunday, and he thinks the 27-year-old Spaniard can still reach a total of "17 or 18 majors."
Mats Wilander, Carlos Moya, Goran Ivanisevic, Chris Evert and Fabrice Santoro were some of the tennis greats who made similar remarks during the Australian Open.
Nadal, 27, had been at his happiest in Melbourne. Last year, he won a total of 10 titles, got back the world number one spot and recovered from a knee injury that had sidelined him for seven months. A stem-cell treatment had removed the pain and reinforced both his morale on court and his good spirits in all aspects of his life.
And then he played that Australian Open final, and his body again gave way. Precisely his strong physical attributes that make him unbeatable sometimes make him strikingly weak.
As he left Australia on Monday, Nadal said his top priority was to find out whether there is "something else" in his back that portends more such problems. "It is hard to process mentally," he admitted.
Nadal presumably still has several seasons left to make his already extraordinary tennis career really legendary, one of the top three or four in history. There is consensus in the ATP Tour that Nadal can still win the French Open several more times, and he also stands good chances with the Australian Open and the US Open.
The record 17 Grand Slam tournament titles held by Roger Federer remains within his reach, although Tomas Berdych was quick to point out one detail.
"No one can say that Roger has stopped and won't try to win another Grand Slam," Berdych told dpa.
The race remains open, and what happened in Melbourne shows that there are variables beyond those that are usually in play.
Laver, who knows a good deal about tennis, said it clearly enough: success comes only when you are injury-free...