Stephen Keshi, who was Nigerian skipper when the Super Eagles last won the African Nations Cup in 1994, believes the chances of a repeat success in 2004 are only 'fifty-fifty'.
"Football is not like mathematics," said Keshi.
"You could have a team which is not playing well who keep winning and winning and they get to the final and win the cup.
"But I would say that Nigeria's chances this year are only probably fifty-fifty."
Keshi said that the side he skippered to victory here in Tunisia in 1994 had greater advantages over the 2004 version.
"This team is very different. We were well-equipped, had great depth and we were a unit with balance.
"There is no comparison between that team and this. I want to believe that the team here is building towards 2006."
Nigeria face their stiffest test of the tournament on Sunday when they take on old rivals Cameroon in Monastir for a place in the semi-finals.
Keshi was speaking after presenting current captain Jay Jay Okocha with the BBC African Footballer of the Year award.
"It was a good decision to vote for Jay Jay," said Keshi.
"I am not saying this because he is a felllow Nigerian and good friend but because he knows how to play football, he's disciplined and a team leader.
"Jay Jay is a phenomenon, I played with him at national level and also coached him, I know what he is capable of doing with the ball and I think he has achieved a lot."