Croatia's Marin Cilic said he hoped to be back to his best and challenge at the top of men's tennis again this season after a tough 2015 following his maiden Grand Slam win.

Cilic defeated Japanese star Kei Nishikori to win the 2014 US Open but he then missed the first three months of last year with a shoulder injury in what turned out to be a disappointing campaign.

But the world number 13, who has spent the past week in Melbourne training on the Australian Open courts, said confidence was high after a positive off-season.

"I was feeling that I was playing better and better towards the end the season," he said before his first match at the Brisbane International.

"Now I have had a lot of time to train, to also work on some things that I wasn't doing so well in the season.

"I think I'm going to be in a really good position, and looking ahead to the next five months up to the French Open, I don't have any points to defend, so it looks really good for me."

Cilic was winless against top 10 players last year and he is seeded third in Brisbane behind Roger Federer, the world number three, and eighth-ranked Nishikori.

But he said the losing streak against top players had given him extra motivation heading into the new year.

"I had a few matches that I should have won against the top guys that I didn't," he said.

"I was just feeling that I'm close to making that step forward, but, you know, I think this year is going to be a bit different."

"(But) I need to step up with my tennis," he added.

"Obviously they are not going to drop down with their level -- overall I need to be the one that needs to step up, to play consistently better.

"I think I need to be also a bit mentally stronger during the matches and getting through the matches with some guys that I should beat more often."

Cilic has a bye in Brisbane before taking on either big-serving Australian Sam Groth or Korea's Chung Hyeon in the second round.
Source: AFP