Thanasi Kokkinakis concedes his debilitating pectoral muscle injury will likely force him to pull out of his hotly-anticipated 'Special Ks' doubles reunion with Nick Kyrgios.

The Special K duo of Kyrgios and Kokkinakis retire in the second set against Vukic and Duckworth, while top Australian seed Alex de Minaur progresses to the third round of the men's singles at Melbourne Park.

Injury-riddled Thanasi Kokkinakis and Nick Kyrgios were forced to retire early in their men's doubles reunion at Melbourne Park after a set and a half.

The apologetic Aussie was plainly ‘shattered’ to tell his great mate Nick Kyrgios it was all over. Thanasi Kokkinakis’ dream of repeating his stunning Australian Open doubles success with Nick Kyrgios has been dashed by his debilitating pectoral muscle injury.

Australian doubles pair James Duckworth and Aleksandar Vukic have eased into the second round of the men's doubles after opponents Nick Kyrgios and Thanasi Kokkinakis retired during the second set of their match on John Cain Arena.

Kokkinakis has been struggling with a pectoral injury for some time, and was forced to withdraw from the Adelaide International last week. He managed to win his first-round singles match at the Australian Open, before suffering a heartbreaking five-set loss in the second round.

It was a miracle that they were even out there, but in the end a win was too much to ask of Thanasi Kokkinakis and Nick Kyrgios, who were unable to overcome their Aus Open injury issues. The first miracle came when Nick Kyrgios and Thanasi Kokkinakis produced Lazarus-like recoveries from their respective death beds to appear at John Cain Arena for their opening round doubles match.

Both Kyrgios (strained abdominal muscle) and Kokkinakis (right shoulder trouble) came into the match dealing with physical issues.

Thanasi Kokkinakis didn't have great news after retiring injured from his Australian Open men's doubles clash with Nick Kyrgios, revealing that he will need "a serious surgical procedure" after going against the doctors and going out to the court.

Thanasi Kokkinakis says a doctor advised him not to play before he and Nick Kyrgios retired injured in the men doubles first round at the Australian Open.

After a brutal five-set defeat on Wednesday evening, Thanasi Kokkinakis admitted it was "unlikely" he would back up to play doubles with good friend Nick Kyrgios. But against the odds, the 'Special Ks' walked out on John Cain Arena on Thursday night for their first-round match.