Rivaldo has challenged Antoine Griezmann to be more bold at Barcelona.
Griezmann struck in this week's Champions League defeat of Borussia Dortmund - a performance which impressed Barca great Rivaldo.
The Brazilian told AS: "He left the bench and scored, which is exactly what is expected of him.
"I think he will eventually adapt to the new reality and start losing that shame that seems to prevent him from developing his football.
"If he gains confidence, he will be important to the club."
