Mane shone in victory over EFL Cup opponents Burton Albion.
Henderson felt Mane was the key man for the side with his direct running and tricky feet giving the hosts a torrid time at the Pirelli Stadium.
"You've seen in the games, Arsenal and today [what he can do]."
Henderson feels Liverpool's squad has the potential to something special this season with Mane one of the key players.
"We missed him at the weekend but we can't rely on him alone," he added.
"We've got a great squad with talented players but he's been outstanding for us and he gives us something different - he can have a big season for us."