Carl Froch and Dillian Whyte are the latest people from the boxing community to urge Mike Tyson and Evander Holyfield to shelve plans of a comeback.
Tyson and Holyfield, who are 53 and 57 respectively, are back in training ahead of possible returns to the ring in exhibition bouts.
The pair could even face each other in a trilogy fight, some 23 years on from their last encounter.
People like Eddie Hearn and George Foreman have also expressed concerns about the former world champions stepping back into the ring.
Froch, 42, said the pair should not even be considering a return.
In a video interview on Twitter, Froch said: “I mean if you’re in your 30s and been retired a year or two I’d say no, don’t bother, because you can never be what you want. If you’re in your 50s you should not even be considering it.
“I’ve seen Mike Tyson, he looks explosive and he looks fantastic for the five second clip I’ve seen on Instagram
“But we’re talking about a three minute round for 12 rounds or a two minute round if it’s professional boxing
“There’s a reason why these people retire and it’s because they can’t do it anymore.
“I don’t know what’s got inside their head, whether it’s money motivated or ego whatever it is there’s a lot of people talking about it and I’m very concerned and I don’t think it’s a good idea.
“You lose your reflexes, you lose your timing and your endurance starts to slip away in your early to mid 30s
“So in your 50s to come back and compete at a top level against young athletes, you’ve absolutely got zero chance.
“I don’t care if you’re name is Mike Tyson, its not happening.”
Dillian Whyte also had reservations for Tyson and Holyfield to come back because of what it could do to their legacy.
Whyte said: “There’s so many different thoughts and ways to think about this.
“If they want to do something for charity in an exhibition match, that’s fine. But as long as they keep it like that and don’t try to get back in the professional ring.
“Because what it does, it diminishes all of their hard work they’ve done over the years.”