Former Rennes coach Philippe Montanier says Ousmane Dembele can be a star with Barcelona.
Montanier worked with Dembele at Rennes before the attacker was sold to Borussia Dortmund.
He said, "Ousmane has had a blistering career.
"He did not have time to consolidate like (Kylian) Mbappé in Monaco. And it's not the same family environment. Ousmane played six-seven months in Rennes, one year in Dortmund and then in Barça. It's enormous.
"You just have to be patient with him."