Robinho, who cost a British transfer record £32.4m when he arrived at City from Real Madrid in 2008, is hoping to secure his place in the Brazil side for the World Cup after falling out of form and favour at Eastlands.
"I have my objective of going to the World Cup and being at my best at the World Cup," said Robinho, after receiving his former number seven shirt from Santos president Luis Alvaro Ribeiro.
"I believe this can be my World Cup. In the national team competition is very big, there are a lot of good players and that had me worried."
Robinho, who scored 83 goals in 190 matches for Santos between 2002 and 2005, hopes to make his debut in the "Classico" against Sao Paulo in the Paulista championship on Sunday.
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.