The retirement of Roger Federer is a sad day for sport, according to his opponent.
The 41-year-old has more men's Grand Slam singles titles than the other two.
"Dear Roger, my friend and rival. I wish this day would have never come," Nadal posted on social media.
It is a sad day for me and for sports around the world.
One of the most celebrated rivalries in tennis history was the Nadal-Federer match.
It's been a pleasure but also an honor and privilege to share all these years with you, living so many amazing moments on and off the court.
There are still lots of things to do together and we will have many more moments to share.
I wish you all the happiness with your wife, Mirka, your kids, your family, and what's ahead of you. I'm going to see you in London.
He won his first Grand Slam title at Wimbledon in 2003 when he was just 16 years old.
Ian Hewitt is the chairman of the All England Lawn Tennis Club.
He lifted the trophy eight times from his 22 appearances at the All England Club.
"He is a champion's champion," said King, who won 12 Grand Slams.
She said that he has the most complete game of his generation and captured the hearts of sports fans around the world.
The former world number one thanked the man on his social networking site. Soon, see you.
"What a wonderful message, full of love, life, hope, passion and gratitude," said the 18 time Grand Slam singles champ. Roger played the game the same way we like to play it. Thank you for all your hard work!
He led an incredible new era of growth and popularity. Few athletes have done something like that.
Annabel Croft is a former British number one tennis player.
He's an icon for the sport.
He was a very strong thinker. He had a big target on his back most of the time. He enjoyed being under pressure.
US Open champion and men's world number one Carlos Alcaraz said that "Federer has been one of my idols and a source of inspiration" while the highest ranked female player thanked him.
The former Swiss Davis Cup captain referred to the tennis player as more than just a tennis player.
He played for 24 years. He played a lot of games. It's hard to imagine. He was a nice guy, he was great to watch, and still is, but he was also a great man outside the court.