Alexander Zverev believes Roger Federer and Rafael Nadal are still the "biggest favourites" at the US Open, but the German senses an opportunity.

Novak Djokovic, Andy Murray and Stan Wawrinka will all miss the year's final grand slam due to injuries, opening the door for up-and-comers like Zverev.

Zverev is among those in New York in fine form, having won titles in Washington and Montreal in the lead up.

The 20-year-old, whose best run at a grand slam was reaching the fourth round at Wimbledon, said he was happy with his recent performances, but he still feels Federer – who has been battling a back injury since losing to Zverev in the Montreal final – and Nadal are the men to beat.

"I played great on the hard courts so far, won two tournaments, Montreal and Washington back to back, which are two huge events, Montreal is Masters series," Zverev told a news conference on Saturday.

"I felt like I could compete and beat anyone during this period of time. I feel quite well coming into this Open.

"I feel different about this grand slam than I have felt before about the grand slams.

"It's obviously Roger and Rafa are the biggest favourites still. I think how the year has been going, they are still on top of everyone.

"But I'm just going to go match by match and hopefully I can get to those guys."

Zverev will face Darian King in his opener at Flushing Meadows, where he has never been beyond the second round.

The talented German said he was confident he could challenge the likes of Federer and Nadal, pointing to previous performances against the greats.

"I have gone deep with them in previous grand slams. I have beaten them in three-set matches. I have beaten them in Masters events," Zverev said.

"I think it all depends on how the match goes. I think it all depends on the day, as well.

"I think we are all playing great tennis over the hard-court swing, so it's more about that than just thinking, 'okay, I'm playing them in a five-set match it's going to be so much different than a three-set match'.

"Obviously it will be a much longer match, but it's not dissimilar. The tennis doesn't change that much."