Thanasi Kokkinakis at centre of fresh Nick Kyrgios drama at US Open

Aussie tennis great Wally Masur has urged Nick Kyrgios to end his doubles partnership with Thanasi Kokkinakis if he wants to win an elusive grand slam singles title.

Kyrgios was left absolutely devastated on Tuesday after crashing out of the US Open in a five-set quarter-final loss to Karen Khachanov.

'THIS IS SAD': Tennis fans left shattered over Roger Federer news

'HARD TO WATCH': Andrey Rublev breaks down in heartbreaking scenes

After his sparkling run to the Wimbledon final in July, many had predicted Kyrgios to go one step further at the US Open and claim his maiden grand slam title.

But things went wrong from the outset on Tuesday as Kyrgios complained of knee pain and had to call a medical timeout after losing the first set.

Speaking after the match, Kyrgios said the knee didn't trouble him as much as the match went on and revealed he was feeling great in the fifth set.

Nevertheless, fans and commentators were quick to suggest that Kyrgios' doubles campaign with Kokkinakis might have added extra wear and tear on his body after a long hard-court swing.

The 'Special Ks', who won their maiden grand slam doubles title at the Australian Open in January, made it to the third round in New York where they were beaten by Lloyd Glasspool and Harri Heliövaara.

Their last doubles match occurred just 24 hours before Kyrgios' quarter-final against Khachanov.

It is common for players to withdraw from the doubles if they make the second week of the singles event at grand slams, however Kyrgios was clearly keen to see how far he and Kokkinakis could go.

The Aussie duo also won the title at the Atlanta Open last month and were among the favourites at Flushing Meadows.

But according to Masur, the extra doubles matches only served to increase Kyrgios' workload to his detriment.

"If the workload is too great and then you're playing the better players in the second week, you can pay a price," he said on Stan Sport.

"He loves playing with Thanasi, they're the Australian Open winners, he brings a lot of energy to the tournament, but there was eight extra sets of doubles.

"I'm not saying that's the reason for it, and I'm really pleased that he did play doubles, but it is very difficult for a top-flight singles player who can win a slam to play both events."

Nick Kyrgios left shattered after loss at US Open

Kyrgios was a broken man as he spoke to reporters in his post-match press conference at the US Open.

“I honestly feel like shit. I feel like I’ve let so many people down," he said.

“Just came out flat, physically didn’t feeling great. Then I ended up feeling great towards the end of the match.

"I'm obviously devastated. But all credit to Karen. He's a fighter. He's a warrior. I thought he served really good today. Honestly probably the best server I played this tournament, to be honest, the way he was hitting his spots under pressure.

"He just played the big points well. Really wasn't anything in it. I'm just devastated obviously. Just feel like it was either winning it all or nothing at all, to be honest.

"I feel like I've just failed at this event right now. That's what it feels like."

When asked about his plans for the rest of 2022, Kyrgios added: “I think pretty much every other tournament during the year is a waste of time. You just front up, show up at a grand slam. It’s what you’re remembered by.

"These four tournaments are the only ones that are ever going to matter. And it’s just like you’ve got to start it all again, and I have to wait to the Australian Open.

“It’s just devastating. It’s heartbreaking. Not just for me but for everyone I know who wants me to win.”

Click here to sign up to our newsletter for all the latest and breaking stories from Australia and around the world.