As if Roger Federer needed another reason not to retire, now he has two.

Federer, the former No. 1 player who held the top spot for a five-year span from 2004-08, recently said he didn't want to retire too early and wants to keep playing, even though 2013 was his least successful year since 2002.

Two other former No. 1-ranked players recently indicated their joy in watching Federer play. Ilie Nastase supports Federer's decision to keep playing, even if his level of tennis may never return to the level it was during his era of dominance.

And former women's No. 1 Chris Evert said she roots for Federer like no other player she has ever known.

1972 U.S. Open champion and 1973 French Open champion Nastase told tennisworldusa.org that Federer should be allowed to play until he's 60 years old if he chooses.

No, Federer doesn't have to prove anything. I wish people wouldn't say that Federer has to retire," Nastase said. "I think Federer should play for as long as he wants. I don't agree with those people who say that you should retire when you are past your absolute best or prime. No, Federer doesn't have to prove anything. Federer can play to 60 if he wants to. If he wants to carry on playing, no one is going to say, 'no, we don't want Federer to play'. He is going to retire when he feels like it.

"I don't think that he has to retire just because he is no longer the world number one. That happens to everybody, as you can't stay as the world number one forever. He retires whenever. Federer said something interesting once. He said that he was watching Rod Laver, and me, and he said he was trying to copy us and to be like us. And that's a great compliment for us."

Evert, winner of 18 Grand Slams over a 17-year career from 1972-89, told stevegtennis.com she feels a bond to Federer.

"Why do I love him? I don't know, I just love him." Evert said. "There is something about Roger which just tugs at the heartstrings. I don't know what it is, I can't say exactly, but he gets to me. Maybe it's because one of my sons idolizes Roger, and I can see similarities between the two. It's almost as though Roger could be my son.

"I've been in this game for more than 40 years, and there has never been a player who has made me as emotional as Roger has, not even close. ... This may sound strange, but his losses affect me much more than my own defeats."