World number four Daniil Medvedev heads into the Australian Open on an ominous 14-match win streak, but played down his chances Sunday of lifting a maiden Grand Slam title.

The Russian 24-year-old has been in blistering form and led his country to the ATP Cup with a 6-4, 6-2 defeat of Italian world number 10 Matteo Berrettini.

It was his 10th victory over a top-10 player in his 14-match run, making him a serious contender for the Australian Open starting Monday.

Asked if he considered himself one of the favourites, Medvedev was reticent.

"I mean, it's not for me to decide. Hopefully I can show a great level like I did these last matches, then I will have my chance to win matches. That's the most important," he said.

"As you know, I always say this: I take it match by match. 

"Every match is tough. You can get injured, you can lose, you can get a walkover. We never know. I just want to be there on the court and try to play some good tennis."

His Russian teammate Andrey Rublev, the world number eight, is in equally good form, winning all four of his matches so far this year on the back of claiming five titles in 2020, more than anyone else. 

They could meet in the last eight at Melbourne Park, a scenario Rublev said was enticing, but not one he wanted to think about just yet.

"It's too far to say something about it now. We have to go match by match," he said. 

Medvedev opens his campaign on Tuesday against Canadian Vasek Pospisil while Rublev faces German Yannick Hanfmann on the same day.

"Daniil has a tough first round. Me, I have as well, the German guy I never seen before, but I heard that he's playing really, really great," said Rublev.

"We'll see what's going to happen. We're not going to meet in second round, so we need to win couple of matches, and is going to be tough matches."

While some top names like Rafael Nadal haven't played this week, the Russian pair have both had four matches but Medvedev said it was hard to know if competing so hard close to a Grand Slam would prove to be advantage.

"It's tough to say because it can both be negative and positive," said the Russian, whose best Slam performance so far was making the final of the 2019 US Open. 

"You get the momentum going, sometimes it helps you. At the same time it's tiring. 

"I've played four tough matches, yesterday especially (against Alexander Zverev).

"We need to see after the tournament if it was a positive thing or a negative one."