The Spanish tennis legend has been limited in terms of his participation on the court in the past two years amid fitness problems and Federer can sympathise with his great rival having been in a similar boat before retiring from the sport in 2022.
Federer told USA Today: "I actually just spoke to him (Nadal) this last week.
"He wanted to ask me something, and we had a chat, and I felt a little bit sorry for him.
"That his summer didn't go as well as planned because, at the French Open he had a tough draw. Olympics, he had a tough draw as well.
"He was hoping, I think, to make a medal."
Nadal has raised doubts about his long-term future in the sport and Federer hopes that he can bow out in style when the time does come.
The Swiss icon said: "He (Nadal) can do whatever he wants. He's been one of the most iconic tennis players we've ever had in our sport.
"I just hope he can go out on his terms and the way he wants to. He's a great guy, great career."
Nadal suggested that he would not be fixating on his future in the sport after missing out on a medal at the Paris Olympics.
The 22-time Grand Slam champion said: "I can’t spend all day thinking about that.
"I come here, and you ask me the same thing every day and in the end it’s very difficult to get back to my best form if I think about whether I’m going to retire or not.
"I have been suffering a lot of Âinjuries the last two years. So, if I feel that I am not competitive enough to keep going, or physically I’m not ready to keep going, I will stop, and I will let you know. But I don’t think every day about if I am retiring or not."
