The mayor's brother and campaign manager made the comments to the Toronto Sun on Friday, hours before the city deadline for who will appear on the election ballot.
Doug Ford, who is a councillor in Etobicoke North currently, said he may run for mayor if his brother doesn't.
Coun. Ford told the newspaper that the mayor is facing "a surgery and chemotherapy and could be on his back for six to eight weeks."
"This decision has not yet been made and there is a lot of pressure because the deadline is in a few hours," Coun. Ford said to the Sun. "We are waiting to talk to the doctors and a decision has to be made."
He also told the newspaper his brother "is in for the fight of his life."
Doug Ford said there will not be two Fords on the mayoral ballot. Either way, Coun. Ford added, he will follow whatever the mayor's decision will be.
"I would jump off a bridge for the guy," he said.
The deadline to add a name to the ballot is 2 p.m. today.