Freddie Roach, who trains WBO welterweight champion Manny Pacquiao, admits that he's concerned after watching several of Jeff Horn's recent fights.
Pacquiao will defend his title against Horn (16-0-1, 11 KOs), an undefeated 2012 Australian Olympian, on July 1 at the Suncorp Stadium in Brisbane, Australia.
Over 50,000 fans are expected to pack the venue and many of them will be in support of Horn, who on paper and among the experts is a massive underdog in the fight.
Roach recently revealed that he was very disappointed with the start of Pacquiao's training camp.
The Hall of Fame trainer said he witnessed Pacquiao have a very difficult time in sparring and also said the Filipino star looked lackluster in training.
After reviewing some tapes of Horn, Roach has become concerned with the Aussie's punching power and overall ability.
"We're not going to take anyone lightly; we never have and we never will. [Horn is] not very well-known, but the thing is, I've seen his last few fights he's won by knockout, and he's pretty impressive, a pretty good puncher and I hope he does come with that style and comes looking for a knockout," Roach told The Sydney Morning Herald.
"Horn looks like he's a little bit of a puncher. One thing about Australian fighters is he'll definitely be in shape – they work hard, their work ethic is good. I've seen a lot of Australians in my gym. I actually have three permanently right now."
Horn's promoter, Dean Lonergan, is very confident that his fighter will send Pacquiao into retirement.
"It's going to be an absolute war and I think at the back end of it we're going to have a brand new champion and a new legend, one that all of Australia can celebrate," Lonergan said.
"I know that's not what Manny Pacquiao wants to hear and I know it's not what [promoter] Bob Arum wants to hear, but at the end of the day it's a new guard, we're going forward."