George Foreman has urged Mike Tyson and Roy Jones Jr. to cancel their return to the ring out of fear for their safeties.
Tyson, 54, and Jones, 51, revealed on Thursday that they had arranged a much-anticipated eight-round exhibition fight for September 12.
Tyson most recently set foot inside the ring 15 years ago, when he quit midway through his fight versus Kevin McBride, while Jones continued to fight often until his retirement in February 2018.
"There's a time when you've got to worry about your health," Foreman told TMZ about the pair's return. "But it's a beautiful thing that they would even come out.
"Maybe they can even name a charity or something for the recipient of the funds. I think it's good to come out, but it's got to be a fun thing, but I hope one does not hit the other.
"I would just tell them it's really dangerous, but when you make up your mind to do something like that, you can't tell them, 'Don't do it.' They're not going to hear that."
Foreman, now 71, said he too considered a return to the ring at the age of 55 but was talked out of it by his wife.
The two-time world heavyweight champion added that letting go of the sport he had pursued since he was a boy was akin to death.
"I was 55 years old. I was in shape and everything," Foreman said.
Referring to his wife, he added: "She said, 'George, isn't that the way you want to leave the sport: believing that you can still do it?' I got closure right there, and I walked away, and it was death to a fighter to realize you're never going to fight anymore."