Josh Warrington insists he has prepared to face the "very best" version of Carl Frampton ahead of their featherweight world title fight in Manchester, England on Saturday.

IBF titlist Warrington told ESPN this week that he had been unimpressed with Frampton's recent performances, suggesting the Northern Irishman, 31, is "not a spring chicken anymore" after losing his unbeaten record, No.1 featherweight status and WBA title to Leo Santa Cruz two years ago.

Frampton (26-1, 15 KOs) has won his three fights since -- against Luke Jackson, Nonito Donaire and Horacio Garcia -- although he has yet to return to the levels of his performance that saw him beat Santa Cruz in the pair's first bout.

But speaking at the fight's final news conference Wednesday, Warrington (27-0, 6 KOs) was adamant he was not taking his opponent lightly ahead of Saturday's fight, which is to be shown live on ESPN+, despite his recent comments.

"I've never said that he's past his best," Warrington, 28, told reporters. "All I've said is you can't judge the performances against Donaire, against Jackson and against the other geezer he boxed in Belfast after a long layoff, to the ones against Santa Cruz. That was when Carl was at the peak of his career. Every fighter has peak years, it's a long career and it's long time to hold that level.

"But me and my team have prepared for the very best Carl Frampton. I'd be a mug to look at him as over the hill or anything like that. I've gone into this training camp preparing for Carl Frampton in his ultimate prime and that excites me."

Frampton countered, "No matter what Josh and his say team, they think that I'm over the hill, I've seen things in the media that suggest that. If the fight does get sticky, if it may turn into a dogfight, I'm prepared for it and that's when they'll realise that I'm not over the hill.

"I'm willing to put it all on the line, anything it takes to win. I've been written off and I think it's unjust. If you look at the fights I've had; [Scott] Quigg, Santa Cruz, Santa Cruz, and I got beat in a close fight the second time by Santa Cruz after beating him the first fight, and people think that I'm done.

"I realistically should have been walking straight back into a world title shot but I've had three titles to get here and I'm not going to let anyone take it away from me. I want this title more than I've wanted any title.

"There are people out there who have doubted me and there are people out there who think that I'm done. This will be sticking the fingers up to them and saying there's plenty left to give."

Carl Frampton and IBF featherweight Champion Josh Warrington after Carl defeated Luke Jackson at Windsor Park in Belfast. Ramsey Cardy/Sportsfile via Getty Images

Warrington comfortably outpointed Lee Selby in his last fight to become a world champion for the first time and says he believes he has more to offer in the division.

"That night in May was a very special night and what you get from that is confidence and momentum and I think that can take you up another few levels and hopefully I can find that this weekend," Warrington said.

"A lot of people still don't know what I'm capable of. No one gave me a chance against Selby, but we ended up winning easily. We've always been able to adapt, people look at me as a come-forward, pressure fighter but I've got different attributes, some stuff I haven't brought to the table. It's about timing as well. I believe it's my time with confidence and momentum all in my stride. I believe I can beat anyone in the world."

But Frampton, a two-weight world champion, has plans to become the No.1 featherweight fighter again, with a third rematch with Santa Cruz and a future date with WBO tile holder Oscar Valdez potentially on the horizon should he defeat the Leeds fighter.

"I've got total respect for Josh, but no fear," Frampton added.

"I need to win this fight to get the bigger fights and that's the carrot dangling. I'm hoping to unify my second division and I'm hoping to fight after Warrington one of the other champions in the division."