Silva, the current PSG captain, drew criticism in some quarters when he skippered Brazil at the World Cup and opted to sit alone during his country's penalty shootout victory over Chile in the round of 16.
Former France international Leboeuf concedes that both centre-back Silva and Sweden international striker Ibrahimovic have significant influence for the Ligue 1 champions, but believes the latter would be a better option to lead the side as he is more capable of keeping his emotions in check.
"The real captain of PSG is Ibra," Le10Sport quote Leboeuf as saying.
"Put Ibra in Brazil's context during the World Cup, he'd keep a cool head. Sometimes attackers are less about the collective, but Ibrahimovic gives guidance to his team-mates.
"Silva has an an attitude problem. You sense he's not invested, sometimes in a panic.
"Ibra and Silva have a real influence when they ask the club for something. They give them what they want."