Girona are taking on-loan Manchester City trio Aro Muric, Yan Couto and Pablo Moreno.
City are hopeful of developing all three players into challenging for a first-team berth in the future.
Moreno was signed from Juventus over the summer as part of an academy recruitment drive at City. Kosovo international goalkeeper Muric endured a difficult loan spell at Nottingham Forest last season.
And Couto is a full-back signed from Coritiba in Brazil for around £5million in July as City beat Barcelona to the 18-year-old's signature.
Girona will compete in the Segunda Division this season.