What began as an innocuous callus on his left hand turned into a gaping wound for Nadal against Grigor Dimitrov in the Australian Open quarterfinals. It eventually produced a pool of blood and, in some minds, represented a potential field-leveler. It remains a painful, performance-impeding blister, all because of the repeated rubbing between Nadal's palm and his Babolat AeroPro Drive.
It was a grisly scene actually, at least in the relatively modest terms of tennis lacerations. Nadal, who is famously focused, was visibly bothered by the discomfort. It didn't help that he was on the court for 3 hours and 37 minutes, during which his gash was re-taped multiple times.
Well it appears that Federer just might (we stress, might) have the upper hand, so to speak, when he meets his longtime nemesis Thursday night in the Australian Open semifinals.
"He's been tough to play against, no doubt," Federer told reporters after his quarterfinal win. "I'm happy I get a chance to play him in a Slam again. I don't remember the last time we played.
"The head-to head record is in his favor. I'm looking forward to speaking to Stefan [Edberg], because when we spoke together, you know, when he came to Dubai and we spoke about the game, we clearly spoke about playing Rafa as well.
"He thought he had some good ideas, so I'm looking forward to what he has to say. Clearly with [coach Severin Luthi], he knows him inside out. I'm looking forward to hear what the boys have to say. We'll prepare. I hope I can get a win. We'll see.
Federer, of course, needs any assistance he can get, considering his dubious history with Nadal. By now you're well aware of their head-to-head numbers:
• Overall: Nadal leads 22-10
• Outdoor hard courts: Nadal leads 7-2
• All Grand Slams: Nadal leads 8-2
• Australian Open: Nadal leads 2-0
So you can see why Federer probably isn't in much of a rush to lend Nadal any of his adhesive tape.
But what we can safely say is that Federer will be in a rush to get to the net when they meet Friday. It has been close to a decade since we've seen him make such a staunch effort to move forward and end points quickly, eschewing the grind-it-out baseline game that has failed him in the past year.
According to ESPN analyst Brad Gilbert, Federer's net game is just one of three reasons he's looking like the player who has 17 Grand Slam titles on his stirring résumé.
"Stefan Edberg has had a huge impact," said Gilbert, who guided Andre Agassi to two Australian Open titles. "As soon as Federer brought him on, it was a new beginning. Edberg was one of the great serve-and-volley players of all time, and he constantly has Federer thinking about closing in and finishing off points at the net."
Against Andy Murray in the quarterfinals, Federer was the aggressor from the outset. He channeled his new coach's philosophy almost flawlessly by approaching the net 66 times, winning 49 of those points.
What about that new gear we've heard so much about?
"I've been saying for four years Federer should have switched to a bigger racket," Gilbert said. "I'm surprised he didn't stick with it for the entire summer [in 2013]. It's really helping him with his return and backhand."
"This might be as good as I have seen him in three or four years," Gilbert added. "He's playing great defense, jump-sliding and hitting those squash shots. He's moving unbelievably well. His back is finally healthy."
Federer's run to the final four in Australia ends a terrifying stretch that saw him go out in the second round of Wimbledon last year and then in the fourth round of the US Open, a sequence of events that left the tennis sphere very much doubting whether we'd ever see another vintage run.
And now look where we are: Federer had won 14 straight sets until Murray took the third in their quarterfinal matchup. And this from a guy who is 32 years and 169 days old. If Federer can navigate past Nadal, he would become the fourth-oldest player to reach the Australian Open final. Federer, for one, knows that these opportunities are precious at this point in his career.
"Yeah, things don't get easier," he said. "But at the same time they might become more enjoyable. Maybe I can play with less pressure. Maybe I just love it. I still love competition. Still feel maybe there's something big around the corner.
"You know, I'm just trying to find out and see if that's the case. I do feel it is. But only time will tell if it's possible or not."
Speaking of time, Nadal is hoping he has enough to heal his latest malady, but as Gilbert said, no other player in the world could have prevailed under those circumstances except him.
"His will and competitive spirit are unlike anyone else's in the game," Gilbert said. "And let's face it, that blister isn't going away. I saw it. It's the size of a quarter. It's nasty."
But in the crucible of sports, stuff happens. For Nadal, considering his long litany of injuries, notably his precarious knees, a hand wound isn't going to keep him from a shot at more history. If Nadal goes on to win the Australian Open, that would give him two titles at each Slam. Only the great Rod Laver can say that. It also would give Rafa 14 major titles, tying him with Pete Sampras for second all time, leaving him only three behind Federer.
If that were to happen, you'd better believe the greatest-of-all-time debate will be as fierce as it has ever been. And considering Nadal's age, 27, and his passion to play as long as he physically can, the possibility of perching himself atop the pantheon of this sport is a very real possibility.
But as provocative as that sounds to us, Nadal is taking his run in Melbourne one blister at a time.
"I feel that with the tape I can lose the racket when I serving," Nadal told reporters after defeating Dimitrov. "That's my feeling, no? The racket can go. That's a terrible feeling for a serve, because then when you have this feeling you are not able to accelerate at the right moment.
"You lose a little bit the coordination. Yeah, that's a big deal. But right, I served slower. I served bad. I was able to win a match against a very difficult opponent, so that has much more value than when everything is great."
This will be the 33rd chapter -- with the Super Bowl looming, we'll give you the Roman version, XXXIII -- in a storied, albeit one-sided, rivalry. The first time Federer and Nadal met was a decade ago in Miami, where, as a 17-year-old whippersnapper, the Spaniard triumphed in straight sets. They last played in Australia two years ago in the semifinals, an ultra-competitive match that Nadal won in four sets. That also happened to be the last time they met at in any major. As it stands right now, Rafa is on a four-match winning streak against Federer in which he's dropped only one set.
Sounds like we know how things are going to turn on come game time. Not so fast, says Gilbert.
"Let me just say this," he said. "Federer is probably considered the slight favorite given Nadal's blister, and if he can pull it off and go on to win the final, you might have to consider this the best win of his career."
And for Fed fans, were it to happen, there might not be enough thank-you notes in the world to express their gratitude.