Filip Hrgovic has said he will "smash the kid" when asked to predict the outcome of Saturday's heavyweight title bout against Brit Moses Itauma.
Hrgovic and Itauma will battle it out for the vacant IBF belt at O2 Arena.
While Itauma is the favourite, at 21-years-old he is less experienced than Hrgovic, 34, who won Olympic bronze in 2016.
Neither fighter had too much to say at Thursday's news conference, but Hrgovic did have some stern words for his opponent, who he has labelled "a kid" and said was "in the clouds" during the build up.
"I'll smash the kid, man," Hrgovic said.
"I just tell you what I think. I think he's a kid, he's not mature enough. I think I'm the man. I'm a much better age, much more experienced. That's it.
"I will smash the kid on Saturday and I'll send him back to high school."
While Itauma has been dubbed the next face of the heavyweight division, Hrgovic has previously said he is "not impressed" with the Brit's rise up the ranks and believes he has had a much tougher journey.
Itauma told reporters earlier in the week that Hrgovic was starting to annoy him with his taunts, but didn't bite at anything his Croatian rival said on Thursday, remaining straight-faced and focused at the news conference.
The Brit could become the second-youngest heavyweight champion in history behind Mike Tyson with victory on Saturday, but said that wasn't on his mind ahead of fight night.
"I'm not trying to become the second-youngest heavyweight champion of the world," he said.
"I'm trying to beat Filip Hrgovic and become world heavyweight champion."