It's about to be announced officially in a few hours.
Ronaldo has just tweeted "More sports in my life. Now it's all-in!" (
https://twitter.com/ClaroRonaldo), and a lot of other clues about it have been popping recently. Leo Fernandez, Humberto Brenes, Akkari, and other PS-related people have replied/retweeted it.
He's probably gonna be the ambassador for the Brazilian market (though he's also a known name worldwide).
ps. nothing has been announced officially yet.