London, UK, 16 June 2015 | AAP

A mentally-wearing Nick Kyrgios says he will switch off tennis completely ahead of Wimbledon after admitting he “didn’t want to be out there” for his first-round loss at the Queen’s Club.

The 20-year-old, who rose to prominence with a stunning upset of Rafael Nadal at last year’s Wimbledon, struggled to get going against French Open champion Stan Wawrinka, going down 6-3 6-4 in just 49 minutes.

Kyrgios, who struggled with an elbow injury in the lead-up to the French Open, was also noticeably under the weather in Tuesday’s loss, coughing and spluttering in the heat.

“I just felt uncomfortable the whole time, really. I’m not feeling great,” Kyrgios said.

“I almost found it difficult to get myself engaged and didn’t want to be there.”

When asked if it was just the flu or whether it was a bigger-picture issue, Kyrgios replied: “I think it’s a bit of both. I have been battling mentally a bit.”

Kyrgios has already flown over a friend, while his father, Giorgos, will arrive next week as he attempts to get his head straight before Wimbledon.

“It’s tough at the moment, like I say,” he said.

While Wawrinka, who last week dismantled world No.1 Novak Djokovic in the final at Roland Garros, was his typically composed self, Kyrgios was erratic.

The Australian’s fearless play against tennis’ biggest names has seen him claim the scalps of Nadal and his childhood hero, Roger Federer, in the past 12 months.

Against the in-form Wawrinka he fell flat.

The crowd roared as he produced booming passing shots, yet those moments of class were overshadowed by overly ambitious between-the-legs shots and drop shots.

Wawrinka pounced on every Kyrgios mistake, snatching a break in the eighth game of the first set while accepting the gift offering of a double fault by the Australian early in the second.