Rafael Nadal has admitted that winning against Bernard Tomic in the first round of the Australian Open will not be easy.

The world number one believes that his 21-year-old Australian opponent is a "big talent" and is aware of the threat that he poses.

"It is not the best [way] I know to start a Grand Slam - playing against a player who is local and who is young, who played great in the past here and who is playing well," Nadal told reporters. "He's in the final of Sydney [International]. It's a tough start."

"He has a big talent, he has a good serve, he's able to play with very good control from the baseline, he has very good [anticipation] of where you are going to hit the ball.

"To [make it] through in that first round will be because I'm ready to compete well. If not, I'm going to be ready to be practising at home. That's all."

The Australian Open gets underway on Monday.