City and Girona are partners, with Guardiola's brother Pere now part-owner. Pep signed up as a member during his visit.
"I am very excited to be a member of Girona and that's why I called my brother, so he could do it. From Manchester we follow the results and watch the games whenever we can and hopefully Juan Carlos Unzué and his players can have a good year," said Guardiola.
"But the League is very long and you cannot think that everything will be done in October. The key is to reach the last matches being ready to fight for promotion and I'm sure that if everyone thinks of that goal they will have options to do so."