Barcelona head coach Javi Hernandez praised Ilkay Gundogan's impact on the team's development.
"He had a very good start to the season. The way he has adapted, his leadership qualities, his ability to pause, his calmness in action - all of this improves our game. He is an invaluable player," Mundo Deportivo quoted Xavi as saying.
Before the start of the season, Barcelona signed Gundogan as a free agent from Manchester City, signing a two-year contract with the 33-year-old.