It comes a day after a major event organiser in China said a meet-and-greet with the forward on Monday in Shanghai was off because he and his advisers were busy with transfer business.
That added to swirling speculation that the unsettled 25-year-old could be poised to join Paris Saint-Germain for a record-breaking 222 million euros.
Footage also emerged of Neymar having a training-ground altercation with new Barcelona signing Nelson Semedo while in Miami, where they play Real Madrid later Saturday in a high-profile friendly.
Then Neymar sent a first message on Weibo, China's equivalent of Twitter, saying: "Greetings to the fans in China! I'm Neymar Jr, this is my official Weibo account.
"I am going to be sharing my own personal experiences here with Chinese fans.
"I'm looking forward to your following and reposting! See you in Shanghai on Monday!"
The message was written in English and Chinese, but gave no further details on his movements in China....