Junior middleweight star Tim Tszyu is only days away from toughest fight of his career.

This coming Saturday night in Australia, Tszyu will collide with former WBC world champion Tony Harrison at the Qudos Bank Arena (Sunday in Australia). The vacant WBO interim-title will be at stake.

Tszyu was scheduled to face undisputed champion Jermell Charlo. The fight was postponed after Charlo suffered an injury in training camp. The winner of Tszyu-Harrison will face Charlo in the coming months.

Harrison is the only fighter to hold a victory over Charlo, who got revenge by scoring a knockout in their rematch.

Tszyu, the son of Hall of Famer Kostya Tszyu, made his United States debut last year, against Olympian Terrell Gausha. The unbeaten Aussie was forced to get off the floor in the very first round to pound out a twelve round unanimous decision win.

"Everything has been on point. I went and researched a little bit about Cristiano Ronaldo. I know he's not a boxer but the way he approaches life is the way I am approaching life right now - as a true, 100 percent athlete dedicated to his craft. Everything. Just the way I eat, when I eat, just true professionalism," Tszyu said.

"I know when I was growing up my dad was an army sergeant with the way he approached life and I'm times two to how he was. The funny thing is that as the rounds go up and up and up, I feel like I don't get tired. My breathing's on point and everything's just running smoothly. Right now I feel like I could run over anyone and it's a good position and feeling to have, especially leading up to such a big fight."