David Haye's shoulder surgery was so severe that three months on he cannot even run, let alone throw a punch, the former world heavyweight champion has revealed.
And Haye admits conflicting medical opinions continue to leave him in the dark on the future of his boxing career.
The 33-year-old underwent a five-hour operation in Germany to repair severely ruptured tendons in his right arm in November.
The Bermondsey-born fighter is refusing to give up on a return to the ring, but said there is no timescale on a potential comeback.
"You talk to 10 doctors, 50 per cent say you can make a recovery and 50 per cent say, 'no you're done, you'll never be able to throw a punch again otherwise your arm will fall out of its socket'.
"It's just down to how the rehab takes, I'm doing that every day, I'm doing the best I can.
"No one knows how it's going to take, no one knows how it's going to heal.
"At the moment I can't throw a punch, so hopefully in a few months I'll be able to throw one, but you never know.
"I can't say 100 per cent yes or 100 per cent no, I'm just taking every day at a time.
"I won't know anything for a good few months yet. My shoulder's bad enough that I can't even run yet.
"That shows you how far away I am from being able to punch.
"It's going to take a little while, but I'm working hard on the rehab."
Haye's shoulder surgery forced him to withdraw from his keenly-anticipated grudge match with fellow Brit Tyson Fury.
Fury has repeatedly offered jibes against Haye's injury and recovery, but Haye shrugged off any criticism, vowing to keep pushing forward with his rehabilitation.
"There's plenty of speculation, but the bottom line is I don't even know, so if I don't know no one's got a chance of knowing," he said.
"I've just got to be patient and keep a low profile, and when I do have news, good or bad, I'll let everyone know.
"Best-case scenario my arm gets back and it's just as good as it was before it busted.
"And then I think I've got a lot left I believe, I think I've got a few more good fights left in me, if this arm can get back on track."
Speaking at the launch of the Rocky Heavyweight Collection on Blu-ray, Haye admitted he treats Sylvester Stallone's much-loved Italian-American battler as a real fighter.
Ranking Rocky Balboa in his top-10 boxers of all time, Haye said aspiring sportsmen and women can certainly take inspiration from the fictional movie character's against-the-odds success story.
"It's no secret I'm a huge fan of the Rocky franchise," said Haye.
"I've been a big fan of Rocky ever since I was a kid. I was a 10-year-old training to be the heavyweight champion of the world, so Rocky was a huge idol.
"He wasn't the most gifted athlete out there, but through hard work and dedication he overcame all the odds.
"Everyone loves that kind of story, and that's what drew me to Rocky in the first place.
"It's definitely still relevant now, and I think youngsters coming into sport can certainly use it as inspiration.
"In my mind Rocky's a real person - he's in my top-10 favourite boxers of all time!"
:: The Rocky Heavyweight Collection on Blu-ray is out now from Twentieth Century Fox Home Entertainment.