The 71-year-old had begged Iron Mike to call off his comeback – but has now changed his mind after seeing him sparring.
Tyson is back in the gym as he plans to compete in a four-round exhibition bout to raise money for charity.
Foreman pleaded with the 53-year-old to keep his gloves off as he has already done so much for the sport.
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But when asked if he had seen the clip of Tyson sparring, Foreman revealed he has had a change of heart.
He told iFL TV: “I was so happy. He looked like he had turned the clock back at least 20 years.
“He was looking fit and those punches were coming sharp.
“If he’s able to go into the woods and dedicate himself to that for about 10 months, he could come back and really be a top contender.”
Foreman became the oldest world heavyweight champion when he beat Michael Moorer, aged 45.
But the 71-year-old claimed Tyson has the ability to break his record and predicted he will not draw the line at exhibition bouts.
He added: “That’s what they do, that’s the way it happens.
“I called Dick Sadler, my original trainer back in the 1960s, I’d just won a gold medal, I said I just want to do exhibitions, that’s all, and learn more about boxing.
“Next thing you know, I’m in with the heavyweight champion of the world.
“So it starts off talking about exhibitions, but then it gets bigger and bigger.
“And Tyson, I would like to see him back in the ring.
“He’s an older fella, but a record is always waiting to be broke.”
But Ricky Hatton has called for Tyson to cancel comeback plans as he fears the 53-year-old could pick up a “serious injury”.
