"I was going for my shots, but missing a bit today". "I didn't expect to play at this level in the first match of the year".
First up, the 36-year-old Swiss will play Ajaz Bedene of Slovenia.
Federer's big concern would be against del Potro in the quarters.
Nadal, who lost to Federer in five sets in a vintage Australian final past year, has opted to join Djokovic at the Kooyong Classic exhibition event for some match practice in the week before the Open.
The Australian Open is the second straight Grand Slam to be badly hit by injury issues.More news: Philip Morris International Inc
Federer though is heading into the season's first Grand Slam with a lot of confidence after leading Switzerland to season-opening Hopman Cup earlier this year. He delayed his return until two exhibition appearances this week.
This was Nadal's first match in a while.
Nadal matched Federer for two Grand Slam titles in 2017, with the Spaniard following up a 10th French Open title with US Open glory in September, proving that the "King of Clay" can still cut it on the hard courts too.
The first Grand Slam of the year is just around the corner and the excitement has already begun among the fans to find the top contenders to win the Australian Open.
That means they can only play each other if they set up a rematch of last year's final.More news: Top honchos exit Disney board
Top-ranked Simona Halep opens against Australian wild card Destanee Aiava, has a potential second-round match against 2014 Wimbledon finalist Eugenie Bouchard, and is in the same half as Garbine Muguruza, the Wimbledon champion. Venus was dealt one of the toughest possible opening draws, facing 77th-ranked Belinda Bencic, a teen prodigy whose ranking fell after undergoing left wrist surgery previous year. The Briton was forced to withdraw two days before the start of the US Open after failing to recover from the hip injury which bothered him during his loss to Querrey.
"There's no easy way to get to the top", Sharapova told the crowd at Margaret Court Arena before the draw. "Actually we didn't have a chance to support each other today because we were playing nearly at the same time but it's always good to have a close friend from your country with you, to be with you, traveling with you, sharing everything", said the 27-year-old Safwat.
The draw for both men and women consists of 128 players. "For me it was not ideal to not be in Brisbane, I would have loved to be there but I had to make a different schedule this year", Nadal said during the week.
"The drive, I still have it".
"Luckily for me, I'm here", Djokovic said after he beat Thiem on Wednesday.More news: What is the Tide pod challenge and how did it start?