Senegal will play their first World Cup match since 2002 when 26-year-old Mane and his countrymen take on Poland in Moscow on Tuesday (16:00 BST).
Cisse captained the 2002 team to the quarter-finals, beating defending champions France in the group phase.
“Mane is unique and cannot be compared to any other Senegal player.
He can make the difference,” Cisse, 42, said.
“He’s already one of the best – you can’t say he’s not.
He plays for one of the most iconic clubs, one of the best in Europe, and he’s top-notch for them.
“He’s absolutely unique because he is so unpredictable, that’s what makes him great.”
Cisse, who spent four seasons in the Premier League with Birmingham and Portsmouth, says Mane has taken his move to Liverpool in his stride.
Mane has scored 33 goals in two seasons since moving to Anfield for £34m from Southampton.
“Despite everything that has happened for him over the last two years, he hasn’t changed – he’s just as humble as he was when I first met him at the 2012 Olympics,” Cisse said.
“Senegal isn’t only Sadio Mane, though, he has a good team built around him and I think it should be a little plus for him that we’re all behind him.”
Cisse said he was confident Africa will eventually celebrate a World Cup winning team.
“I’m sure Senegal, Nigeria or another team will be able to win the World Cup just like Brazil and Germany – we have no complexes about this,” he said.
“You can see African players with all the best teams in Europe – we just need more African coaches.”
Salif Diao also played for Liverpool and Senegal and believes Mane and his team-mates can prosper in Russia if they put team ethic above individuals.
“This squad has more quality in depth compared to the 2002 squad but that 2002 team maybe had more maturity,” said the former midfielder.
“The togetherness has to be massive and stronger.
Thinking about the national team and the flag and families back home.
“When African teams go to the World Cup they’re representing their own countries and Africa so the pressure is even more.
“You can’t do it all on your own so you really need to think of the team effort.
The team is bigger than the individuals.”