The centre-back was forced off just 30 minutes into Sunday's match at Levante, where an astonishing 5-4 defeat ended Barca's hopes of an unbeaten top-flight campaign at the penultimate hurdle.
Barcelona did not give a timeframe on Vermaelen's estimated return date following tests on Monday and his condition will be a concern for Belgium head coach Roberto Martinez.
The 32-year-old, who has battled numerous injury problems over recent years, featured in the Red Devils' successful World Cup qualifying campaign.
Belgium are due to name their squad for Russia 2018 on May 21.
He is contracted to the Catalan side until 2019.