Rafael Nadal
Rafael Nadal of Spain celebrates a point in his semifinal match against Grigor Dimitrov of Bulgaria on day 12 of the 2017 Australian Open at Melbourne Park, Jan. 27, 2017 in Melbourne, Australia. Cameron Spencer/Getty Images

Legacies will be on the line Sunday in Melbourne as the two men widely regarded as the greatest to ever pick up a tennis racket go head-to-head in an Australian Open final that is as eagerly anticipated as it is unexpected.

When Roger Federer and Rafael Nadal missed large chunks of last season through injury, the prospect of their rivalry, perhaps the greatest the sport has seen, having another airing on such a stage appeared a remote possibility.

Instead, once the dust has settled and the winners’ trophy has been held aloft, the Grand Slam title battle between the two will have altered significantly. It will read either a surely decisive 18-14 in Federer’s favor, or Nadal will have closed the gap to 17-15 to potentially reopen the debate over the greatest player in history.

And, despite all their achievements, a win for either tennis legend could go down as their greatest.

It is, therefore, perhaps easy to understand why Andy Roddick, a former rival of both men, called the prospect of their meeting in Melbourne perhaps “the biggest match ever in Australian Open history — and maybe Grand Slam history."

It will be their ninth encounter in a Grand Slam final and one that even the men involved have had no hesitation in admitting they did not expect.

Both had been written off in the past couple of years. For Federer, already past an age at which mere mortals had ceased to be competitive in top-level tennis, every Grand Slam defeat since his last title in 2012 was viewed by many as his last chance to add to his record haul of major titles. For those skeptics, his announcement following last year’s Wimbledon that he was taking the rest of 2016 off to fully rehabilitate a knee injury confirmed that he would forever be stuck on 17.

For Nadal, age was less a factor than the wear on his body of his relentless intense style which sees him extend every sinew of every muscle for every shot and for every point. Last spring, having seemingly recovered his fitness and the resulting dent to his self-belief after a string of injury problems, he suffered a wrist injury that forced his withdrawal from the French Open and then Wimbledon. Having rushed back for the Olympics, he too watched the closing months of 2016 from the sidelines.

Both hoped the layoffs would enable them to beat the best again at some point in 2017. Neither thought they would be in a position to claim a major title just a couple of weeks into the season at the Australian Open.

But having already outlasted the two players who have taken their mantles at the top of the rankings – Andy Murray and Novak Djokovic – Federer and Nadal proved in the semifinals that they still have plenty left in the tank. First, Federer, a lowly 17th seed, held off a fight back from compatriot Stan Wawrinka to win in five sets. A day later Nadal, seeded ninth, had the physical and mental edge over five sets against a player five years his junior, Grigor Dimitrov.

The pair will now meet in their record-extending ninth Grand Slam final and first since Nadal came out on top at the 2011 French Open. Indeed, Nadal has been victorious in six of their previous eight finals. Four of those losses came at Roland Garros, and, speaking immediately following his win over Wawrinka, Federer admitted that he may have allowed those early battles on Nadal’s favored surface of clay to dictate the tone of their rivalry.

In the press conference later, though, the 35-year-old said he expects those meetings to have little bearing on Sunday’s encounter on the quick hard court of Rod Laver Arena.

“Now it's a different time,” he said. “A lot of time has gone by. I know this court allows me to play a certain game against Rafa that I cannot do on center court at the French Open.”

On that issue, both men are in agreement.

“It was a long time ago,” Nadal said following his near-five-hour epic against Dimitrov Friday. “It’s a different match, different moment for both of us. I think this match is completely different than what happened before.

“It’s special. We have not been there in that situation for a while, so that makes the match different. I really don't think about what happened in the past. I think the player who plays better is going to be the winner.”

Match Time: Sunday, 3:30 a.m. EST
TV Channel: ESPN
Live Stream: Watch ESPN