Nick Kyrgios’ return to the Australian Open is over after he and partner Thanasi Kokkinakis stopped playing while trailing in the second set of their first-round doubles match.

Nick Kyrgios and Thanasi Kokkinakis's bid to repeat their Australian Open doubles triumph of 2022 ended in retirement in on Thursday when the latter was unable to continue their first-round tie.

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.

Kokkinakis was hampered by a long-standing pectoral injury as he went down 7-6 (7-3) 3-6 6-3 5-7 3-6 to Jack Draper in a four-hour-and-35-minute heartbreaker. Speaking after the match, Kokkinakis said he wouldn't even be able to lift his right arm to serve on Thursday night.

An anguished Thanasi Kokkinakis has cast serious doubt on his playing future as a chronic pectoral injury threatens to sideline him for a significant period.The 28-year-old suffered a heartbreaking 6-7 (3-7),

Thanasi Kokkinakis was warned for "bending the rules" as he called the physio during his marathon battle with Jack Draper in Melbourne.

A seething Thanasi Kokkinakis has described his ongoing pectoral muscle issues as “physical and mental torture” after losing a five-set epic at the Australian Open.

Thanasi Kokkinakis says he feels like he’s “letting people down”, with the doubles reunion of his 2022 Australian Open winning partner Nick Kyrgios “unlikely” after he suffered a recurrence of a pectoral injury in his second round loss at Melbourne Park.

Australia’s Alex de Minaur has also come out in defence of fellow country Thanasi Kokkinakis, who has received criticism about prioritising exhibition events before preparing for the mega-events.

Jack Draper said the abuse he received during his thrilling five-set Australian Open comeback over home favourite Thanasi Kokkinakis inspired him to raise his level as the British No 1 reached the third round of the grand slam for the first time.

Jack Draper conjured the spirit of Andy Murray to claw his way back from the brink of defeat against home favourite Thanasi Kokkinakis at the Australian Open. Two years ago, Murray famously recovered from two sets and a break down against Kokkinakis to win a second-round match that finished at 4.05am.

Australian tennis star Thanasi Kokkinakis has stunned his opponent with an amazing act of sportsmanship at a critical moment of their second-round Australian Open clash. British No.15 seed Jack Draper was serving at two sets to one down, and trailing by a break in the fourth when he was about to be denied a certain point after a long rally.