However, endless hours of hard work and the strong-willed belief of a champion means the Spaniard will be contesting a sixth Australian Open final - 13 years after winning his first and only title at the Melbourne slam.
Nadal started the season after missing a chunk of the 2021 tour due to a lingering foot injury that forced him to skip Wimbledon, the Olympics and the U.S. Open among other events and raised doubts if he would ever come back to the court.
But the 35-year-old has produced some incredible tennis over the past few weeks to enjoy a 10-match winning run, picking up an ATP 250 title in Melbourne before the year's first major.
"Honestly the doubts are going to be here probably for the rest of my career," Nadal said referring to his foot problem after his 6-3 6-2 3-6 6-3 win over Italian Matteo Berrettini in the semi-finals.
"But for me it's amazing, and I'm super happy to be able to compete for the last three weeks at the level that I am doing. It's surprising for me to be able to play at the level."
His last tournament before arriving in Australia was in August in Washington. Nadal said he was unable to practice for many days.
"I worked hard for a long time every single day," said Nadal, whose Grand Slam haul includes a record 13 French Open titles.
"When I was not able to play tennis I was working hard in the gym. I worked the proper way, and I hold the positive spirit and attitude to give myself a chance to be back."
A win in Sunday's final against U.S. Open champion Daniil Medvedev will give Nadal a 21st major title and break a three-way tie with Novak Djokovic and Roger Federer for the men's major record.
"I just feel happy to be part of this amazing era of tennis, sharing all these things with another two players. That's it," he said.
"In some ways it doesn't matter if somebody achieve one more or one less. We did amazing things and things that will be very difficult to equal. I don't think much about all this stuff."
Russian Medvedev will play Nadal for the title after a stirring victory over Greek fourth seed Stefanos Tsitsipas in the semi-final.
The world number two reached the decider for the second year in succession after by defeating Tsitsipas 7-6(5) 4-6 6-4 6-1.