Flintoff has shed 45lbs over four months of training under the guidance of former world featherweight champion Barry McGuigan in preparation for his pugilistic bow against American novice Richard Dawson.
The fight has been almost universally panned by the sport’s inner circles, however, with promoter Frank Warren and British heavyweight Danny Price described it as "car crash TV".
Another matchmaker, Frank Maloney, branded it a "scandal" and called for British Boxing Board of Control chairman Charles Giles to be sacked for granting the former England cricket captain a license to box.
The 34-year-old nonetheless insists his desire to try his luck in a second sport are sincere.
"You couldn't go through this for a TV stunt," he said.
"If I was looking for a publicity stunt I'd have picked something easier. There's other things I could have done.
"There's been criticism of things I've done in the past. I'm just getting my head down and doing the best I can.
"I appreciate that people want to protect the sport they're involved in. I'd be the same with cricket.
"I'm hoping this is something where boxing is celebrated because it's not my intention to cheapen the sport or show it up.
"We want to show the sport in the best possible light because ultimately I'm a boxing fan as well."
McGuigan also defended the plans, branding criticism as being motiviated by ‘jealousy’ at the preview screening of 'The Gloves Are Off', documenting the crossover attempt.
"What we're doing is the opposite to cheapening the sport, it's promoting it. You see the pain and anguish Freddie goes though," McGuigan added.
"How can that be negative in promoting the sport? To say it cheapens boxing is a complete and utter load of nonsense.
"It's a case of the green-eyed monster I'm afraid. Freddie's worked his nuts off and we're promoting the sport in a very positive way.
"We could have done white collar or amateur boxing, but that's not real. This is real."
"Let's be honest, Freddie is a novice. There's been a monumental change physically," he continued.
"Technically he has a lot to work on, but we'll keep at that. He's a great pupil. He's not a natural but he works very hard. He gets there because he's so determined."
Flintoff’s cricketing career boasts 79 Test and 141 one-day international appearances, and he admits boxing could be his biggest sporting challenge yet.
"In cricket the mental aspect was tough but this has taken that to a whole new level," Flintoff said.
"You're up and down all the time, you get nervous before a sparring session, you're on a high when you're in there and then an hour later you're flat.
"The diet's had its' moments....eating steak at 5:30 isn’t the easiest. Giving up booze has been all right though. It's been a lifestyle chance.
"One of the things I had to overcome is that I'm not the most confrontational bloke.
"When I played cricket every now and then I would be, but it didn't bring out the best in me.
"There has to be a ruthless streak in the ring, so there's been a change mentally to achieve that."