Barcelona president Josep Maria Bartomeu admits it's critical they secure Marc-Andre ter Stegen to a new deal.

The German is now the outright No1, despite the arrival of Jasper Cillessen from Ajax.

Bartomeu has declared Ter Stegen as a "fundamental" member of the team.

"He is a fundamental part of the club's future. Like Rakitic, Suarez and others. Like Leo (Messi).

"He is a lynchpin and our commitment to him is strong," said Bartomeu.