World number one Rafael Nadal suggested a two-year system would be a fairer way to decide men's tennis rankings after his Serb rival Novak Djokovic said the current 12-month system was cruel.
Djokovic lost his number three ranking to Andy Murray despite landing a second title of the year in Belgrade at the weekend and reaching the last three Masters Series finals.
Nadal said he had talked to Djokovic about the issue and agreed the current system of defending points won a year ago needed changing.
"I think a ranking based on two years would be much better in terms of being relaxed and, from my point of view, would allow me to lengthen my career," Nadal said after crushing Austria's Juergen Melzer at the Madrid Open.
"It's an important change."
Players on the ATP tour have to defend the points they earned during the same week a year earlier, so the reigning champion at an event can only maintain his points tally, not improve it.
"Playing three Masters Series finals in a row and winning a 250 event (in Belgrade) is incredible success and even then you are dropping a spot down in the rankings," Djokovic said.
"That shows how cruel the ranking system is in this sport."
"Federer or Nadal have been winning four or five grand slams in a row and they haven't won a single point," Djokovic added after beating Spain's Oscar Hernandez in the second round.
Nadal 'n Djokovic
"I don't want to create any controversy because in the end it looks like I'm the one causing it," said Nadal, the vice-president of the ATP Player Council below Federer.
"I've been saying for some time now that for me, it would be better to have a two-year ranking system; it would be better for the players."
Nadal, who has on the whole managed to avoid serious injury problems although his knees occasionally become a weak point from the wear and tear his athletic style puts on them, added: "If you have an injury it's (the absence) not going to hurt you as much. You could also choose a bit more where you play and where you don't play.