Joe Calzaghe's predecessor as WBO super-middleweight champion has echoed the Welsh boxer's view that age will be Bernard Hopkins' downfall.
Former champion Steve Collins, who is the same age as Hopkins, told the BBC's Sport Wales programme: "43 years is a very old man in boxing."
At 36, Calzaghe, who fights Hopkins early on Sunday in Las Vegas is seven years younger.
"Hopkins is making a mistake...Joe is too fit, too hungry," Collins said.
"I am the same age as Bernard Hopkins - I couldn't do it," Collins tells the programme, adding it would be a "great fight" for Calzaghe.
"Hopkins is going to lose. Everything about the fight tells me that it's a win for Joe.
"I'm the same age as Bernard Hopkins and I couldn't do it again no matter how much determination or how much belief I have. You know, 43 years is a very old man in boxing."
Even though they were boxing at the same time in the 1990s, Calzaghe never had the opportunity to challenge Collins for his title and the retired champion said he saw parallels with his own career in that Calzaghe was now looking for "that big name fight".
But he said Hopkins would have his excuses ready if he lost to Calzaghe, even though Collins thought Calzaghe would have beaten Hopkins even if the pair had met 10 years ago when Hopkins was "in his prime".
"He'll turn around and say: 'I stayed around too long, I'm 43 years old, I would've beaten this guy in my prime, I took it because I thought I had one last fight left in me'...and that's so frustrating."
His advice to Calzaghe would be to "do what Joe does best".
"Just overwhelm him - pressure, punches and make those 43-year-old legs suffer."
And the battle over age has been taking place in Las Vegas as well with Hopkins playing down the age gap.
"Joe is not a spring chicken, he's 36-years-old," said Hopkins.
"In boxing numbers, 43 is old and 36 has got to be knocking on the senior citizen door. I am already in the senior citizen hall if it means anything."
Sport Wales is on Thursdays at 2200 BST on BBC 2W and BBC Two Wales. The Sport Wales - Calzaghe Special is repeated on BBC 2W on Friday, 18 April at 2200 BST.
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