Roger Federer has opened up about his relationship with Rafael Nadal in a wonderful insight into the long-time rivals and great friends.
Federer and Nadal have been the story of 2017 in the tennis world, coming back from the brink of retirement to dominate the tour.
The World No.1 and 2 have swept the grand slams this year, with top dog Nadal winning the French and US Opens, while Federer took out the Australian Open and Wimbledon.
The tennis greats also delighted their legions of fans at the inaugural Laver Cup recently when they teamed up for the very first time in a doubles match for Team Europe.
Now as they head into the final stages of 2017 with the No.1 ranking still in play, Federer has spoken how their relationship has developed over the years.
"At the beginning he was very shy and respectful with other top 10 players, and especially because I was No. 1," Federer recently told Tennis World.
"Then as the time went on his personality increased and he started playing his chances.
"It was interesting to see him growing up until that he became the champion he is today.
"We had hard and painful battles on court, issues as well, but there was always an enormous respect between us.
"We shared many strong moments on court and off court in a very friendly way. As soon as we grew up, I realised how much Rafa was important in my career.
"He will forever be my ultimate opponent. He was the one who helped me to improve the most and to be a better player.
"And at the same time I say if he didn't exist, I would have not won so much (laughter). Rafa's presence was an extra motivation."
Federer also spoke about what it was like to finally play on the same side of the net with Nadal.
"We had different feelings than the past. We were a team, training together.
"In such situations on the practice court you are almost happy when they beat you because it means they are well-shaped. Usually you do not like to lose but here we trained like a team does.
"These are little things that on the Tour don't happen because you think about yourself, you want to choose your hours and want to win practice session matches.
"Spending a week like this in group with Rafa and others, almost all of them who are top 10 players, was very special."
The Swiss great says he sees his rivalry with the Spaniard as up there with other great match-ups like John McEnroe and Bjorn Borg.
"They have incredible stories," he told AS at a film festival where ‘Borg vs. McEnroe’ was being screened in Zurich.
"It was more rock and roll, let’s be honest. Today it’s very professional - but still we have a good time.
"But it’s also very similar to some extent. We can be rivals and yet get along, and I think me and Nadal have shown that, as McEnroe and Borg did."