Rafael Nadal believes he can still contend for grand slams as he continues his return from injury.

The Spaniard has slipped to ninth in the world rankings after a wrist injury had a huge impact on his 2016.

Nadal feels he can challenge Andy Murray and Novak Djokovic and add to his 14 grand slams.

"You never know, but if I believe that I could not have this chance during the next 11 months I will not be here probably, I will be at home fishing," he said. "My real goal is try and compete for important things and I know if I want to compete for important things I have to try and beat these guys.

"If I'm working hard, have the motivation and passion to keep going, it's because I feel if I am healthy and I can work the way I want to work, I can do it."

Djokovic and Murray are expected to be the main contenders for the Australian Open, starting 16 January.

Nadal said it was tough to predict the year's first grand slam, while backing up-and-coming stars Alexander Zverev and Nick Kyrgios to potentially shine.

"It's not like when you have six months of the season when you know how people are playing," he said. "But, having the results of the first week of the year, Novak won [the Qatar Open], Andy played the final, Kei [Nishikori] was playing well too.

"Zverev is a player who can play so good and if Nick is healthy and if he's playing well then obviously playing at home, he's a player you need to think about. Let's see.

"Let's see how things are going. Let's see how Roger [Federer] comes back. I didn't have a chance to watch him play but I heard he's playing well and I hope to be ready for the action too."