Rafael Nadal believes the Davis Cup must be played over a two-year period if the competition wants to see the world's best players continuing to feature.

This week, it was announced that proposals to change the tournament to a best-of-three sets format had been unanimously supported by the International Tennis Federation (ITF).

Those alterations will be put to the ITF AGM in August, where they are expected to be formally ratified.

The ATP Tour's busy schedule means some of the sport's most high-profile figures have opted to miss matches in the past, with world No.1 Andy Murray not featuring for Great Britain in its first-round clash with Canada last month.

Nadal, who has won three finals with Spain, says holding the Davis Cup on an annual basis is detrimental to the tournament's chances of seeing the top players competing regularly.

"In my opinion it is not about best-of-three or best-of-five. In my opinion, it's about we cannot have a Davis Cup champion every year," he said.

"That devalues the competition. If the top players are not playing very often, then you are making something not good.

"Davis Cup is a beautiful competition, a very emotional competition. To maintain that level of emotion, that level of quality of tennis, you need to do the things for the best players.

"The best players need to feel comfortable playing every time that Davis Cup is going.

"I don't mean one year Davis Cup, one year no Davis Cup. I mean, for example, two ties per year. That will be something reasonable and players will be very motivated to play Davis Cup.

"You know, you finish Davis Cup, last tournament of the year, December, and then in January you start again. And it's tough."