Nadal and Federer have always offered each other the utmost respect but the Spaniard on Sunday opened a lingering wound by accusing the 16-time grand slam winner of not doing enough given his lofty status to push for change on issues such as prize money and the strains of life on tour.
Nadal, who beat qualifier Alex Kuznetsov 6-4 6-1 6-1, said in his press conference on Sunday: "His position is easy: do not say anything, all positive, I am a 'gentleman', others get burned."
The world number two admitted on Monday night he had been wrong speaking publicly rather than seeking out Federer personally.
"Yesterday [Sunday] what I said, I said but I was probably wrong telling you because these things must stay in the locker room," said Nadal.
"I have always had a fantastic relationship with Roger and I still do.
"We can have different views about how the tour needs to work, that's all.
"I feel sorry for saying it because I should have said it to him personally."
Federer was diplomacy personified after easing past the challenge of Alexander Kudryavtsev 7-5 6-2 6-2.
"Things are fine between us, I have no hard feelings towards him," he insisted.
"It's been a difficult last few months in terms of politics within the ATP, trying to find a new chairman and CEO, that can get a bit frustrating sometimes.
"He's mentioned many times how he gets a bit frustrated through the whole process and I share that with him.
"But for me, nothing changes in terms of our relationship. I'm completely cool and relaxed about it. He seemed the same way - or at least I hope so."
Federer also rubbished suggestions he stood apart from the majority of the players, who attended a mandatory ATP meeting in Melbourne on Saturday night.
"I was in the meeting and I completely understand and support the players' opinions," he added.
"I just have a different way of going at it.
"I think of the players first and usually when I take decisions, I think of the lower-ranked players first. I hope they know that."
A strike has been mentioned in some quarters but that was not a route Federer felt would benefit the game as a whole.
"It's such a dangerous word to use, that's why I always say 'let's try to avoid it as much as we can'.
"I think that would be best for everyone, fans, tournaments and players.
"If there is no avoiding it, I'll support the rest of the players but I just think we need to think through how we do it."
Having attempted to play down one potential issue, Nadal was presented with another after revealing he was suffering from a knee injury which almost forced him out of the tournament.
"I had a fantastic week of practise with no pain but yesterday [Sunday] afternoon the strangest thing happened. I was sitting on a chair in the hotel and I felt a crack on the knee. I stood up and the knee felt a bit strange. I moved it and I felt unbelievable pain.
"I had to go to the hospital for an MRI and yesterday [Sunday] evening I was not 100% sure I would play but I had a lot of treatment and the MRI was positive.
"I am really happy that today [Monday] I was ready to play and played a fantastic match."
Aside from Federer and Nadal, the day belonged to home favourite Bernard Tomic after the Australian came from two sets down to beat Fernando Verdasco 4-6 6-7 (3/7) 6-4 6-2 7-5 in an epic struggle.
There were also wins on day one for Tomas Berdych, Nicolas Almagro, Mardy Fish and Juan Martin Del Potro.