Jonathan dos Santos has struggled for minutes at Barca this season.
But Giovani, currently on-loan at Racing Santander, told fifa.com: "I speak to him a lot and tell him he needs to be patient. He's at the best club in the world, no doubt about that, and has huge stars for team-mates. It's a great opportunity for him to be able to train with them.
"He needs to keep cool, play well for the B team and wait for his chance, which I've no doubt will come."