'I expect more from Andy' – Djokovic

World No 3 knows what it takes to reach the top and he thinks it's time for close friend Murray to realise his potential

It is probably safe to say that Andy Murray has a pretty good idea how far he can go in the game, but it never hurts when one of your peers backs up your own feelings with a ringing endorsement of your ability.

The world No 3, Novak Djokovic, whose career has grown alongside and then ahead of Murray's as the Scot sat out for four months with a wrist injury last year, believes it is only a matter of time before Murray joins him in the world's top five.

"I expect more from Andy," Djokovic said as he completed his own preparations for the year's first Grand Slam event. "It's a matter of consistency. In today's tennis, you can't rely on one, two or three good results, you have to do it more often. I think Andy has great mental strength and he is ready to make it. I expect him to get to the top five this year."

It is little wonder that every time Djokovic's name is mentioned in this country, Murray's is not far behind. Born just a week apart, the pair were contemporaries in the junior ranks and emerged on to the senior tour at pretty much the same time.

The Serb broke into the world's top 10 a few months ahead of Murray but, restored to full fitness and with a title already under his belt this year, the British No 1 seems ready to close the gap. For Djokovic, that would be just fine.

"We met in Tarbes, in France, in the Under-12s," he said. "We played the tournament there. Then we played tournaments together for six years, all the junior events we'd been through. Then for some stage when I was, I think, 16 or 17, he was not showing up so much. He was in Barcelona practising, so we didn't see each other so much. Then he started to do well, to win some Challengers. I got faster to the top 100, then he just came as well.

"He's a very talented player and he has a lot of potential," Djokovic added. "Last year he had problems with the injuries. It was not easy for him to hang in there. He almost reached the Masters. He was just one match away. He wants to prove himself. If he stays away from the injuries, he has all the elements and all the things he needs to be there, to be a top-five player. I think he has proved that many times in the past two years."

Djokovic has beaten Murray in all three of their meetings as professionals, including back-to-back semi-final wins last year in the United States at Indian Wells and Miami, both Masters Series events. Too many more wins like that would put pressure on their friendship, one might think, a suggestion that Djokovic laughed off.

"We have known each other for a long time and have never had any problems," he said. "We have a nice relationship. It's not a matter of who is doing better or worse, if you have a real friendship, then that friendship doesn't depend on who's doing better, it's something else. It's really good to see that someone you grew up with is doing well."

While Roger Federer and Rafael Nadal mopped up the Grand Slams in 2007, Djokovic was the new kid on the block, winning two Masters Series titles and reaching his first Grand Slam final, at the US Open. While another year along those lines would satisfy him, Djokovic is an ambitious man and he knows that to be considered in the same breath as Federer and Nadal, he needs to win a Grand Slam title.

To that end he has been expanding his horizons, adding more net-play to his already developed baseline game. "I've been working on serve and on volleys," he said. "I want to use my opportunities in the game because I have good groundstrokes and I open up a lot of chances to go to the net and finish the point early, but I am not doing it. That's what I've been working on in the last couple of months with my coach.

"I am feeling more confident on [volleys]. It's still a process. There are a lot of things to work on, especially that movement and that mental liberation in the matches. You can't compare practice to the match, because matches are what is important. That's where I need to step it up and it's all about the mental strength so I am able to do that."

Having admitted he was close to exhaustion when he lost all three of his matches at the Masters Cup in Shanghai in November, Djokovic had a shortened off-season. But after two-and-a-half weeks of training, he chose the Hopman Cup in Perth as the place to start his competitive preparation and won all his singles matches as Serbia reached the final of the mixed competition, losing to the United States in the final.

"I have high goals for the Australian Open," he said. "If I have another year like 2007 I would be satisfied, but I know I can do more."