In a statement on his website, David Haye said:
“I genuinely believed the shoulder injury wasn't that bad...But the doctor sent me for a detailed MRI scan and within 24 hours I was told the full extent of the damage. Twenty-four hours after that I was in the operating theatre.
“It's a crushing blow for me. I had big plans for next year and the ultimate goal was to win back the world heavyweight title, something my amazing fans deserve.
"What I didn't anticipate was that this year would be the unluckiest of my career and that a number of injuries would disrupt my plans so much.
"Perhaps it just wasn't meant to be. The boxing Gods keep hinting that maybe enough is enough and that it's time to finally hang up my gloves.”
More top news
The Metropolitan Police said the building material was found in the force's former training facilities.
The toddler was seriously injured when one of the cars rolled and trapped him between the vehicles in a private car park
The millionaire winner is one of 10 lucky players from the EuroMillions Mega Friday draw on 28 November.