Nick Kyrgios' foul language prompted several apologies from Eurosport commentators during his Australian Open first-round clash with Jacob Fearnley on Monday.

The Aussie lost the first set in front of his home crowd and battled with the abdominal strain which saw him pull out of an exhibition match against Novak Djokovic in the lead-up to the first Grand Slam of the season.

Kyrgios put his hand on his abdomen after virtually every point and was unable to unleash his full serving power on British hopeful Fearnley. At one stage in the first set Kyrgios was heard saying "it really hurts" and "I shouldn't be out here".

After struggling his way to six games apiece, Kyrgios was dominated in the first-set tiebreak and unloaded his frustration within earshot of the courtside microphones.

He said: "Just keep f***ing serving, alright? I'm here now. I'm here now so I may as well just keep serving."

Eurosport commentator Mikey Perera then jumped in: "You can see Nick Kyrgios is starting to unload again. I'll keep apologising, everybody. It might still keep on coming, the bad language from Kyrgios. He's just venting to his team."

Commentators Perera and Barry Cowan also questioned why the chair umpire turned a blind eye to the bad language and opted not to warn Kyrgios.

Injuries restricted the 29-year-old to just one competitive singles match in the 18 months prior to his Australian Open return, and he has only played two competitive singles matches since October 2022.

Kyrgios narrowly lost out to big-serving Frenchman Giovanni Mpetshi Perricard at the Brisbane International in December, before his abdominal injury struck.

Fans turned out in their thousands to see him back at the Australian Open for the first time since 2022. And the former Wimbledon finalist believes the sport will be better off for his return to action.

"I think we watch sport because we want personalities," he said last week. "Me being back, I think it adds a few question marks to what is going to happen today. I love that.

"Every time I step out on court, I don't know if I'm going to be super controversial in a good or bad way. I think it's good to be back. I think it's important. I think the sport was getting a bit mundane."