Melbourne VIC, Australia, 10 October 2016 | AAP

Australian Davis Cup captain Lleyton Hewitt has urged young star Nick Kyrgios to take the next step and mount a serious challenge for the Australian Open 2017 crown.

Kyrgios won the biggest title of his career on Sunday when he defeated Belgian David Goffin to claim the Japan Open in Tokyo.

> READ MORE: Kyrgios captures Japan Open crown

The win lifted Kyrgios to No.14 in the world, with Hewitt confident he is closing the gap on the elite group of players at the top of men’s tennis, including world No.1 Novak Djokovic.

“At the moment he’s showing that he’s good enough to make the quarterfinals at the Grand Slams, but he’s got to take that next step now and really push to towards the semis and then the finals,” Hewitt told reporters on Monday.

“But you’re going to have to beat a few good players along the way, you’re going to have to be able to bounce back after five-set matches physically and mentally, and that’s something that he’s getting better at.

“He’s certainly in that next group, there’s probably the big four or five (players) at the moment who keep putting their hands up and winning those titles.”

The mercurial 21-year-old has regularly drawn criticism for his well-documented on court outbursts, but Hewitt believes he is maturing as a player and as a person.

He said Kyrgios was a positive influence on the Australian team in September’s World Group Play-off win over Slovakia in Sydney and had committed to making Davis Cup a focus in 2017.

World No.23 Bernard Tomic will be Australia’s other main hope in the men’s draw at Melbourne Park in January.

But Hewitt admitted Tomic had some work to do in the off-season after an underwhelming US Open campaign.

“He was playing pretty well going into the US Open then had a disappointing loss in the first round,” he said.

“He’s got to regroup, I think, and probably physically improve a bit better to be able to last over five sets and be able to back up.

“But Bernie always seems to come out and play extremely well throughout the Australian summer.”

Hewitt doubts he will make an appearance in the doubles draw at Australian Open 2017, with the first round Davis Cup tie against the Czech Republic his focus.