The Belgium international has not played a competitive fixture for Barca since joining from Arsenal on a five-year contract in August due to a hamstring injury he picked up playing for Belgium at the World Cup.
However, the 28-year-old returned to full training earlier this month and scored playing for Barca B in their 6-0 friendly win over Indonesia Under-19s on Wednesday, a match that also saw Luis Suarez score twice.
Vermaelen could now come into contention when Barca welcome Granada to Camp Nou in La Liga on Saturday.
"The Barça first team returned to training on Thursday morning after drawing 0-0 with Malaga the night before, and there was good news waiting for [head coach] Luis Enrique," read a statement on Barca's official website.
"New signing Thomas Vermaelen has been declared fully recovered from the hamstring injury that has kept him sidelined since playing for Belgium at the Brazil World Cup."
Goalkeeper Jordi Masip has also stepped up his recovery from a fractured finger.
