Nadal takes on unpredictable Russian Mikhail Youzhny in the first round in Melbourne on Monday.
The 2009 champion won his ninth French Open title last year but lost in the fourth round at Wimbledon before spending the majority of the remainder of 2014 on the sidelines due to a wrist injury and appendix surgery.
“The first round is always very difficult,” Nadal said. “Youzhny is a tough rival who knows how to play well in important matches. It’s a special match for me because the last six or seven months I played only four matches.
“Every match is tough for me as it is like we are starting everything again. We will see how I am. I am doing the right things in practice to try to be competitive and I am confident with the last few days that remain I can improve my performance and hopefully be ready.
“Every match is tough when you are in shape, so imagine when you have hardly played for six or seven months. I have to try my best, play with the best attitude and if things are not going the best, I must try to be very positive and help myself to be competitive.”
Nadal was speaking at an event to promote the Connected Racquet of sponsors Babolat, where he was joined by fellow player Caroline Wozniacki.
Wozniacki was forced to withdraw from a recent event in Sydney due a wrist injury, but said: “It’s feeling good now and I feel 100 per cent ready to play. Hopefully I can get off to a good start to the season.”