While Kyrgios is among the most recognised players at Melbourne Park, Jaziri is at the opposite end of the spectrum.

As fans flocked to court 23 to watch Kyrgios hit with teenage buddy Thanasi Kokkinakis on Thursday, Jaziri practised in anonymity ahead of his first-ever third-round appearance at a grand slam.

But popularity will count for nothing when the 31-year-old Tunisian tries to deny Kyrgios a likely last-16 shot at Roger Federer on Sunday.

At 31, Jaziri may well be playing the finest tennis of his life.

His standing as the game's world No 75 is only six places below his career high of three years ago.

Maybe his appointment last year of Australian coach Dejan Petrovic has helped his game.

Perhaps copping a controversial one-year ban from Davis Cup in 2013 has too, not that the suspension was any of his doing.

Jaziri was drawn into a political controversy when the Tunisian tennis federation ordered him to withdraw from a Challenger tournament in Uzbekistan to avoid playing against Israeli opponent Amir Weintraub.

The ITF exiled Tunisia from the competition over the boycott.

Kyrgios is dealing with his own Davis Cup issue right now, with the Australian No 1 surprised to learn after his impressive second-round defeat of 23rd seed Ivo Karlovic that his captain had been critical of the teenager's on-court conduct.

With Kyrgios fined for destroying a racquet during his first-round win, Rafter said he hoped the 19-year-old would learn to control himself a little more.

"Say again?" Kyrgios said when told of Rafter's hopes.

"Are you asking me if I'm going to mature?

"Um, geez, I don't know. I don't know what to say to that. He has his own opinion, I guess."

Time will tell if Rafter's input proves a distraction because Kyrgios shapes as a hot favourite to beat Jaziri and a shock loss would only prompt more questions. AAP