World number one Rafael Nadal remains confident he will be ready for the Australian Open after making his return from injury with a loss.

Nadal suffered a 6-4 7-5 defeat to Richard Gasquet at the Kooyong Classic on Tuesday in his first match since the ATP Finals.

The Spaniard has reportedly still been struggling with his knee injury, but he appears ready to go for the year's first grand slam starting Monday.

Speaking after his loss to Gasquet, a player he has beaten all 15 times they have played in official events, Nadal said he was feeling good.

"I'm good. I am here. If I am not feeling good, probably I wouldn't be here so that's good news," the 16-time grand slam champion told Channel 7.

"My idea is just to keep practicing hard the next couple of days to be ready for the beginning of the Australian Open."

Nadal added: "I'm very happy to be in Australia again. It was a long year last year so I had to start the preparation a little bit later than usual.

"But I'm here, I arrived with plenty of time and it's a good day to start feeling again the feelings of playing a match.

"Even if it's not official, it was still a good test for me and a good practice so that was the most important thing."