"He's held all four (Slams) at one time so he's already done that portion of it. But he just won the Australian, so now he's in line to win a (calendar) Grand Slam. It's a long way to go, he's only got one, but this is probably, for him, I would think, the toughest match. There are so many good players out there that are playing on clay. That’s why today the clay court is probably one of the toughest ones for a player to win.
On the greatest of the ‘Big Three’:
“You know, they all play a little differently. I think you look at the three of them, at Novak and Rafa and Roger. To me, they are three just huge champions.
“I don't know what their record against each other is all the time, but it's amazing to see players like that that are so in love with the game. They're prepared to put the effort in and know about the game, as well as being able to play it at its best.
"I don't know that I put one above the other because of the fact that tennis was just so fortunate to have, with (Andy) Murray in there as well, four great champions that are representing the game of tennis. Right behind them is another group coming up.
"I always thought that someone like Roger Federer was, just the way he plays and what he does around and off the court, a well-rounded champion.
"I think all of them are just brilliant on the court!”
On the ageless Federer:
“It's amazing. After so many tournaments won, to see him back off and then see himself at 35 or 36, think to himself, ‘I like this game so much that I'm prepared to put the effort in, to learn how to play the game with my body in today's world.’ It's uncanny how he's pulled it all together.