Busquets picked up a thigh problem in his side's thrilling 3-2 win over Valencia on September 1, and withdrew from the Spain squad as a result.
But after sitting out his country's FIFA World Cup qualifier against Finland on Friday, Busquets has now trained with his club.
Barcelona's official website said the 25-year-old "took part in some of the session" and there were no hiccups for him.
Defender Dani Alves sat through a physio session as club doctors continue to work on his troublesome ankle.
Alves missed Brazil's friendly against Australia due to the issue, which Barcelona staff believe could be tendonitis.
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