Former Australian Davis Cup captain Pat Rafter commented on Greek Australian tennis player Nick Kyrgios’ series of ugly tantrums on the court this year.

Currently the subject of two investigations, Kyrgios is already under fire for dubbing the ATP as ‘pretty corrupt’ during the US Open and for his meltdown in Cincinnati where he branded Irish umpire Fergus Murphy a ‘potato’ and a ‘f***ing tool’ before he broke two racquets. He has already been fined $167,000 for the latter.

Regarding his accusations towards the ATP, Kyrgios issued a half-hearted apology, claiming the ATP was guilty of ‘double standards’ when handing down punishments.

Rafter said that he doesn’t understand why Kyrgios hasn’t been suspended yet. “On paper, it looks like he should be suspended to me,” he said.

READ MORE: Kyrgios fined $A166,000 for explosive behaviour at Cincinnati Open [VIDEO]

He added that Kyrgios “draws a crowd, but at this stage do you say, ‘Is the crowd more important or are you trying to uphold a certain protocol and a standard the players adhere to?'” said Rafter, the former world No 1.

Kyrgios is currently ranked higher than any other Australian male tennis player at No 27, and presents a headache to Tennis Australia.

Rafter said that he quit as Davis Cup captain after the 2015 Australian Open, mainly as a result of his difficulty in dealing with Kyrgios and Bernard Tomic.

READ MORE: Kyrgios slammed as a spoilt little ‘Greek’ brat on national TV