The Northern Irishman, 31, fights the once-great Donaire at Belfast’s SSE Arena for the interim WBO featherweight title knowing a high-profile victory will revive his career.
Should he succeed Frampton has next been promised WBO featherweight champion Oscar Valdez or the winner of May’s fight between Lee Selby and Josh Warrington for the IBF title.
He said of his Filipino opponent: “People are asking me, ‘Am I studying him a lot? Am I watching a lot of his fights?’
“To be honest I’m not, because I grew up watching him. I grew up being a fan of his. I know how he fights, I know what he does. I’ll catch up and recap on some of the things he does, but I know how Nonito Donaire fights.
“I’ve believed it from the start (that I would beat him), when Donaire was mentioned – we’ve talked about fighting each other for a long time, even at super-bantamweight, but nothing really came of it – I’ve always believed I can beat guys like Donaire and I believe it even more so now.”
Increasing Frampton’s confidence against his 35-year-old opponent, who at his peak was considered one of the world’s finest fighters, is the benefits he has felt since introducing altitude training to his preparations.
Even if he wins the interim title, however, he will not again consider himself a legitimate world champion.
Saturday’s fight is his second under new trainer Jamie Moore and new promoter Frank Warren since his split with Shane and Barry McGuigan, and he said: “I’ve had a new approach. We’ve been training at altitude.
“We went to Tenerife for a few weeks, over on Mount Teide, every other day we were pretty much up and down Mount Teide. It’s 3,500 metres above sea level, and then when I came back to Manchester we’ve been using an altitude chamber, because you lose the positive effects of altitude training after a week if you don’t continue to use it.
“We’ve been doing two sessions a week in the altitude chamber since we came back, and I feel better than I’ve ever felt. I’m recovering quicker, and able to perform in the red zone for a long period of time, and don’t feel like I’m fatiguing as much as I once was. It’s definitely been very beneficial.
“It’s something Jamie’s done in his own career as a fighter, and we all know how fit he was. It was hard graft, but I’ve been recording and tracking my heart-rate, and I seem to be reaping the rewards because I’m recovering very quick. That was the objective, and it’s worked.”