Daniil Medvedev knows he has not performed to the best of his abilities at grand slams this season after his US Open title defence was ended by Nick Kyrgios.

Medvedev, who will also concede his spot at the top of the ATP's world rankings, has only won one of the four finals he has reached in 2022.

His record in the majors is a particular frustration for the 26-year-old. After losing to Rafael Nadal in the Australian Open final, Medvedev has reached the fourth round at Roland Garros and the same stage at Flushing Meadows, while The All England Club's ban on Russian and Belarusian athletes prevented him from competing at Wimbledon.

With Novak Djokovic unable to play in New York due to his COVID-19 vaccination status, Nadal, Carlos Alcaraz or Casper Ruud will become the world number one after the US Open's conclusion on Sunday.

"I mean, now that you say it, I remember it," Medvedev said in a press conference when asked how it felt to give up the number one spot.

"That's not nice because honestly after such a match, when you lose in a grand slam... I'm trying to look good here, but I'm disappointed.

"[I'm] not going to cry in the room, but I'm a little bit disappointed. For a few days I'm going to be just a little bit sad, looking at my phone, my laptop or watching some series.

"Yeah, it was not the first thing on my mind walking after the match, saying, 'Damn, I will not be the world number one anymore' – I actually don't know which place I will be. Probably three or four. I guess Carlos will pass me. I don't know actually.

"But that's motivation, try to do better. Obviously it was the last slam of the year. I didn't do well enough. Didn't win in Australia when I had the chance. Didn't get the chance to play at Wimbledon.

"Roland Garros, lost in the fourth round. Here, fourth round. Yeah, I should do better, should get more points if I want to be world number one again."

Medvedev went down 7-6 (13-11) 3-6 6-3 6-2 to Kyrgios, who has a 4-1 winning record against the Russian.

Asked if he thought it was Wimbledon finalist Kyrgios' best display against him, Medvedev suggested the Australian came close to replicating the form of greats Nadal and Djokovic.

"Yeah, it was a high-level match," he said. "[I] played Novak, Rafa. They all play amazing. Nick played kind of their level, in my opinion.

"He has a little bit different game because he's not a grinder in a way, [but] at the same time he can rally. He's tough to play.

"He has an amazing serve. He plays well, has every shot. It was a really high-level match from him.

"If he plays like this until the end of the tournament, he has all the chances to win it, but he's going to get tough opponents."