Rafa Nadal has always seemed much older and wiser than he really is. He could out-run and out-think most men when he was still just a boy starting out on the professional circuit.

Despite playing in the same era as Roger Federer, he started racking up major titles faster than his greatest rival. At last year's Australian Open, Nadal captured his sixth Grand Slam at 22.

The Spaniard is back to defend his title this year but his Grand Slam tally has not changed after a year plagued by injuries then self-doubt. He is still just 23 but has already been forced to start reflecting on past achievements.

Twelve months ago, he was on top of the world, holding the Australian Open, French Open and Wimbledon titles at the same time.

Federer was left sobbing as Rod Laver presented the Australian Open trophy to Nadal and suddenly everyone was talking about the Spaniard's chances of completing the calendar-year Grand Slam.

Now, the talk has shifted to whether Nadal can ever get back to his best, let alone scale greater heights and even the Spaniard is unsure about his future.

"Right now my goal is try to be in the fourth round of the Australian Open. That's my goal right now," he said after crushing Slovakia's Lukas Lacko 6-2, 6-2, 6-2 in the second round yesterday.

"To be No 1 again, that can't be a goal. It is not possible ... if you're not winning important tournaments, you're not going to have any chance to be No 1.

"My real goal right now is just try to be competitive in every tournament that I play and feel when I go on court I can win against everybody."

During his absence, Nadal had the chance to reflect on his achievements so far and he quickly came to realize he should have no regrets if he never won another Grand Slam.

"I feel very happy what I did in this sport. I'm still really happy with what I am doing," he said. "I'm 23 years old, having 15 Masters 1000 and six Grand Slams, that is more than what I expected all my life.Nobody's going to take those titles."