Tyson Fury declared 'medically unfit to fight'

— -- Heavyweight world champion Tyson Fury pulled out of his rematch with former champion Wladimir Klitschko on Friday because Fury is "medically unfit to fight," his promoter said.

The fight had been scheduled for Oct. 29 in Fury's hometown of Manchester, England.

Multiple sources with knowledge of the correspondence between Fury's camp and Klitschko's camp on Friday said it included a letter from Fury's doctor. The letter said Fury had mental health issues and would be "unavailable for the foreseeable future."

Mick Hennessy, Fury's promoter, released a statement Friday afternoon, but he did not divulge Fury's medical issue.

"It is with the deepest regret that we have to announce that the world heavyweight championship rematch between Tyson Fury and Wladimir Klitschko will not be going ahead," Hennessy said. "Tyson has, this week, been declared medically unfit to fight. Medical specialists have advised that the condition is too severe to allow him to participate in the rematch and that he will require treatment before going back into the ring.