Tony Harrison hasn’t underestimated Tim Tszyu.

The former WBC super welterweight champion simply doesn’t think Tszyu has accomplished anything to warrant getting an opportunity to fight for Jermell Charlo’s four 154-pound championships. Detroit’s Harrison has stated that so often during the buildup toward his own fight with Tszyu on Sunday at Qudos Bank Arena in Sydney Australia, that he feels fans and media have misconstrued his comments.

Harrison (29-3-1, 21 KOs) refused to call Tszyu a “great fighter” during their final press conference Friday. A shirtless Harrison, who mocked Tszyu for being “corny” while they were seated outside in a park in Sydney, repeatedly referred to the unbeaten son of Kostya Tszyu as a “competitive fighter.”

“I mean, Tim is undefeated,” Harrison said. “Tim’s been [in with] 21 guys in front of him and he beat ‘em all. That’s why Tim’s here. Tim has a great promotion behind him, he has great management behind him and a great name to go along with everything else. So, I’m not saying Tim is short of a competitor. He’s a very competitive fighter. But like I said, to fight for all the belts next, I’m not discrediting him as a fighter. Like everybody’s trying to spin the words. Y’all do everything to make [headlines], but y’all tryin’ to spin my words, like I’m saying Tim is a sh!tball. And I’m not saying that.

“I’m saying he is a very competitive fighter, but to fight for all the belts he hasn’t fought anybody [on] the competitive level nor a top 10 to be fighting for all the belts. That’s exactly what I’m saying. But he’s had 21 guys in front of him and he beat ‘em all. That’s why he’s sitting up here right now. But the question is, what is he gonna do Sunday night? And I think that’s the question that I’m gonna answer for y’all.”

Tszyu (21-0, 15 KOs) undoubtedly is taking a risk by boxing the only opponent who has beaten Charlo (35-1-1, 19 KOs). Oddmakers have still installed Tszyu as almost a 3-1 favorite to defeat Harrison, despite that Tszyu’s most noteworthy wins have come against Terrell Gausha (23-3-1, 12 KOs), Dennis Hogan (31-4-1, 7 KOs) and Jeff Horn (20-3-1, 13 KOs).

Sydney’s Tszyu, 28, and Detroit’s Harrison, 32, will fight for the WBO interim junior middleweight title. Tszyu, the WBO’s mandatory contender in the 154-pound division, was supposed to challenge Charlo for his IBF, WBA, WBC and WBO belts January 28 in Las Vegas, but Charlo suffered two fractures in his left hand while sparring a few days before Christmas, which caused an indefinite postponement.

Because Tszyu hasn’t fought since he unanimously out-pointed Gausha last March 26 at The Armory in Minneapolis, he pushed to fight for the WBO interim championship next. The Tszyu-Harrison winner will likely box Charlo next, on an undetermined date in July.

Showtime will televise Tszyu-Harrison live Saturday night in the United States (10:45 p.m. ET). Tszyu-Harrison also will headline a FOXTEL Main Event pay-per-view event Sunday afternoon in Australia.

Keith Idec is a senior writer/columnist for BoxingScene.com. He can be reached on Twitter @Idecboxing.