Sport says the Belgian is set for hamstring surgery in Finland and the recovery period could be as long as five months.
The former Arsenal captain has decided to take the surgery option after suffering a setback last week, having joined first team training for the first time.
Vermaelen will be operated on by Sakari Orava, who in the past has performed surgery on former Barca midfielder and coach Pep Guardiola.
The defender has managed just a handful of minutes for Barca B this season against a Philippines youth team.
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