Perhaps with an eye on the No. 1 ranking, Grigor Dimitrov says he will attempt to crack the Top 5. Currently No. 11, the Bulgarian says he has to be more consistent and more aggressive.

"There is always possibility for everything, I would say," Dimitrov said. “I think the first step is definitely Top 5. From there you can sort of see the end, and that's the top. In order to do that, you need to win Slams and big tournaments. That's just proven. There is no other way. There is no shortcuts. Play your best tennis, give your heart out, and anything can happen."

Last year, the 23-year-old posted strong results, reaching the quarterfinals of the Australian Open, winning Acapulco, Queen's Club, and Bucharest, and upsetting Andy Murray in the Wimbledon quarterfinals before falling to Novak Djokovic in four sets. He also reached the semifinals at the Toronto Masters.

"I think it was my best year, that's for sure,” said Dimitrov, who faces Martin Klizan in the second round of Brisbane. "Still, there are a lot more things that I want to achieve. In a way, I don't want to be greedy now for that, but I'm really happy that I was injury-free, and I could complete a really good season with a lot of good wins. There is just a lot of tournaments to be played, so let's see how the year will be."