A nagging wrist injury forced defending champion Nick Kyrgios to withdraw from the Mexican Open during his first round match in Acapulco on Wednesday, with the injury casting doubt on his involvement in Australia’s Davis Cup qualifier against Brazil in Adelaide next week.

The 24-year-old Australian, retired hurt after losing the opening set 6-3 of his first round match against Frenchman Ugo Humbert, prompting the local Acapulco crowd to boo him as he left the court.

Kyrgios has been hampered by the wrist injury since the Australian Open in January, forcing his withdrawal from two US hardcourt tournaments leading up to the Mexican Open where he was the sixth seed. During the first set against Humbert, Kyrgios showed visible discomfort especially when going for his forehand shots. He took a medical time out to have his wrist strapped.

In a post-match interview, Kyrgios defended his retirement and expressed anger at the crowd’s negative reaction to his retirement, accusing them of being disrespectful.

READ MORE: Nick Kyrgios’ efforts for Canberra tourism in #holidayhereCBR campaign

“I’m not healthy. I tried to come here, I tried to play. I’ve been doing media for the tournament, I’ve been helping out. I tried to play, I tried to give the fans a little bit of tennis. They’re disrespectful, so I honestly couldn’t give a f***.

“It’s tough, I’m injured, but people with the fires lost their lives, lost their homes,” he said.

“I’ve got a sore left wrist. It doesn’t even compare to what’s going on back home. Hopefully I’ll take a week off and I’ll be right for Indian Wells and Miami and I’ll try to come back. As of now, I can’t play. He’s a great player, he’s young, he’s coming up, he’s had a great couple of weeks. I’m not healthy enough to go out there and compete and win matches like that at this stage.”

Kyrgios entered the Mexican Open tournament as defending champion having defeated Germany’s Alexander Zverev in last year’s final. His withdrawal is expected to result in his ATP ranking dropping to 38.

READ MORE: Nick Kyrgios sets the court on fire at Melbourne Arena as he plays for bushfire relief