Haye's February 8 match against fellow Brit Tyson Fury will now be cancelled.
It's the second time Haye has had to pull out of the fight; he previously cancelled in September after sustaining an eye injury.
More top news
The 20-year-old was found fatally wounded on Roth Walk, near Finsbury Park, north London at around 3am on Saturday, Scotland Yard said.
Police have arrested a man wanted in connection with a burglary at the home of pensioner Richard Osborn-Brooks.
The rally comes after it emerged that the Home Office destroyed thousands of landing cards documenting the arrival of windrush-era migrants