Sharpe believes the defender can prove the club's most successful of their summer signings.
He told Omnisport: "Ibrahimovic is the big star, like Pogba, but the one who is currently above them is Bailly.
"If he continues in this way, then United has a jewel."
Sharpe added: "The team looks very strong across the board. The manager has reinforced the team in different positions with players of top quality."