His grand slam comeback is just one match old, but Nick Kyrgios says he may have played his last singles tie at the Australian Open. After a disappointing straight-sets defeat to Scot Jacob Fearnley marred by more injury struggles, Kyrgios declared that his body is unlikely to sustain another tilt at singles at Melbourne Park.

“Realistically, I probably can’t see myself playing a singles match here again,” the Australian said. “I mean Nick Kyrgios without his serve, I’m probably not a threat to many players.”

The bombshell statement comes after two years of recovery following wrist surgery. Yet it was an abdomen strain that caused the 29-year-old more grief on Monday night at John Cain Arena. World No 92 Jacob Fearnley made the most of the Australian’s lack of service polish and mobility to win 7-6 (3), 6-3, 7-6 (2).

“All the niggles, I guess my body compensating with the wrist is tough, but, yeah, it’s just not enjoyable for me,” Kyrgios said. “It’s not enjoyable to go out there and not think tactically and not think I’m enjoying the atmosphere, or where am I going to hit this ball. It’s like, ‘what am I doing to manage my body?’ This is painful. OK, I can’t do this because this hurts.’ That’s not tennis to me, that’s not sport.”

His comments followed a largely underwhelming contest, that only fully engaged an expectant crowd in the third set. The Scot – whose four-year US college career has masked his Edinburgh accent – held his nerve in front of a hostile turnout to end Kyrgios’ much-hyped return. “You never really know what you’re going to get when you play Nick and he played some unbelievable tennis,” Fearnley said.

The Australian’s performance certainly was difficult to believe. Although his abdomen injury limited his serve, he smashed five aces and wasn’t broken in the first set. Rather, Kyrgios – who has seemed to move well and swing freely in practice throughout the week – looked out of touch with his return. The Scot lost just four points on his first serve in the 88 minutes it took to claim the two first sets, sending down 13 aces and dissolving the crowd’s enthusiasm.

“I knew that I couldn’t really show any emotion, because I felt that the crowd was just going to eat that alive,” Fearnley said. “So I was fighting to just stay composed, and stay calm and not give them anything.”

Only belatedly did Kyrgios seem anywhere near like his old self. He had groaned and grimaced, shaking his head and clutching at his stomach all night. But when he broke back for 3-3 in the third set, the crowd stood and roared. “I go out there tonight, and I’m I’d say probably 70, 65% of my capacity, and for them to really see me fighting and still giving me that energy, it meant a lot,” Kyrgios said.

For 15 minutes the fans could dream of the most unlikely of upsets as Kyrgios rediscovered his role as showman, producing a behind the back shot and under-arm serve. There was even a set point opportunity when the Scot was rattled. But Fearnley steadied, resumed control and dominated the decisive tie-breaker.

“It was difficult to keep my composure for sure, I had to fight to do it,” the Scot said. “I knew that I wasn’t going to be able to get [the crowd] on my side, so I just had to focus on myself and try and play my game, and do the best I could to kind of move past every point.”

The Australian said he still plans to play singles for the rest of the year including at the grand slams, and will attempt to compete in the men’s doubles this week with Thanasi Kokkinakis despite his abdominal injury.

Fearnley, who meets France’s world No 78 Arthur Cazaux in the second round, said it was “cool” to play the Australian, even if the atmosphere made it difficult. “If that is his last match, I was glad that I was able to play him before he before he went out,” he said. “He’s obviously a massive name and someone that on the court I have 100% looked up to.”

Kyrgios said he knew that this might have been his last appearance in singles at Melbourne Park, and although he was in pain he didn’t want to quit for the sake of the crowd. “I wanted to give them two and a half hours of tennis rather than retirement [from the match] … that’s shit.”

Virtual queueing technology at Melbourne Park had been rolled out last year, allowing fans to reserve their space at the evening session at John Cain Arena during the day without having to line up. But the system had failed on Sunday, forcing organisers to return to physical queues.

By early afternoon hundreds were congregating, hoping to see Kyrgios’ return. They didn’t know it might also be his swansong. “I feel like I’ve given a lot of my life to tennis, and I’ve tried to give them a show every time I go out there,” Kyrgios said. “And I know I didn’t do a great job tonight, but there were moments that were special to me that I won’t forget.”