Bernard Tomic’s commitment to tennis is expected to be questioned again as he pulled out of his first-round match due to “unbearable heat”.

Tomic lost the first set to American Donald Young in a tiebreak, however, the Australian looked disinterested throughout much of the set before eventually withdrawing from the game.

Tomic withdrew from the match citing “unbearable heat” as the reason, this seems more questionable as the heat in Acapulco at the time was 27 degrees - much less than the heat in Melbourne Park, where it can hit heights of 40 degrees.

The withdrawal means that Tomic is ruled out of a potential second round clash with controversial and fellow Aussie Nick Kyrgios, who is playing today.

Last year, Tomic reached the final in Acapulco, where he had to play five games, but he eventually lost out to Austrian Dominic Thiem.

Tomic returned to court later after his retirement with doubles partner Paolo Lorenzi and fell to another defeat, 7-5 6-2, against American giant John Isner and Spanish star Feliciano Lopez.

Tomic’s commitment to tennis has been questioned before after he retired from four ATM fixtures during 2016.

Tomic is currently ranked at number 41 in the world after sliding down the rankings, and with the clay-court season drawing closer, it is hard to see his situation improving.

Tomic is also the record holder for the fastest loss in an ATP match, after losing to Jarkko Nieminen in an astonishing 24-minute match back in 2014.