The Spanish international came through a full training session ahead of their Camp Nou tie with Jagoba Arrasate’s side tomorrow and he could be included in Koeman’s squad.
Busquets has not featured for La Blaugrana since picking up a knee injury on international duty with La Roja earlier this month, missing two games as a result.
According to reports from Marca, he is line to come straight back into the Barcelona starting XI this weekend, with Koeman in urgent need of a win.
Just one win in their last six league games means Barcelona have slipped down to 13th in the table and the Dutch boss is expected to rotate his options.
POSSIBLE BARCELONA STARTING LINE UP V OSASUNA
Ter Stegen; Dest, Lenglet, Mingueza, Alba; De Jong, Busquets; Messi, Pedri, Dembele; Griezmann