Roger Federer and Novak Djokovic believe early withdrawals due to injury should prompt action from grand slam organisers after the superstars were left joking about the need to practice together at Wimbledon. 

Spectators felt short-changed on Tuesday when they saw less than two hours in total of Djokovic and Federer's respective first-round ties on Centre Court.

Djokovic was leading 6-2 2-0 when Martin Klizan retired due to a sore leg and Federer was only on court for 43 minutes before Alexandr Dolgopolov said at 6-3 3-0 down that an ankle problem meant he could not continue.

Caroline Wozniacki's encounter with Timea Babos was moved to the main show court after Djokovic and the Swiss great had a brief chat to discuss the prospect of heading back out for a knock.

The crowd voiced their disapproval when Federer's match was brought to a premature end on day two at the All England club.

And with questions asked over whether their opponents were fit enough to start the matches, both Federer and Djokovic feel the issue over players - who still collect prize money - pulling out when not fully fit for majors should be addressed.

Federer said: "The question always is, should they have started the match at all? That, only the player can answer really, in my opinion. You hope that they would give up their spot for somebody else, even though they deserve to be in there, but fitness not allowing them.

"I don't know how much of that has something to play with it. On the ATP level we have a different sort of situation, whereas if you can't play, you still get your prize money twice in the year. Maybe the grand slams should adopt some of that, then maybe we would eliminate maybe half of the players.

"Some of them, maybe something really did happen. Now you're thrown in the same basket, so that's rough."

Djokovic said: "Maybe it should be addressed. I think the new rule that the ATP has reinforced allows players who deserve already, who have made it to the grand slam main draw, to get what they deserve, but at the other hand allow someone else to play if they can. I support that kind of rule."

The Serb added: "It's really odd that Roger's result and my result more or less was the same. We had a little joke about it in the locker room, saying we should maybe play a practice set on the Centre Court, have the crowd stay. But they had another match."

Federer said of his chat with Djokovic: "When I walked up, the chairman said, 'You guys should go and play for another set and a half'. I said, 'Yeah, let me go try to find Novak.'

"I found him in the locker room. I told him, 'Maybe we should go out and play another set'. [But] it's not going to happen."