Now fully recovered from a long-term hamstring injury, Dembele produced his best performance for Barca in victory at Malaga last weekend.
The France attacker impressed amid claims of him struggling to win over senior teammates and coach Ernesto Valverde.
A source told L'Equipe: "Many things were said, but Ousmane remained insensitive and took refuge in work. He did not panic.
"This was his first serious injury and it's part of an apprenticeship..."