The forward left Camp Nou in 2011 for Roma but is currently on loan at AC Milan, where he has struggled for first team appearances with the likes of Stephan El Shaarawy, Mario Balotelli and M’Baye Niang ahead of him in the pecking order.
"I hope Bojan will return one day," Fabregas told Marca. "When he was here before, he was too young to stand out.
"But I think now he has matured enough to do well at Barcelona."
The 22-year-old made his debut for Barca in 2007 at the age of 17. He went on to score 41 goals in 163 appearances in all competitions during his four seasons with the club.