Hazard recently joined Real Madrid in a £88m deal after months of speculation.
And Emerson says the Belgian said a heartfelt but abrupt goodbye to the Blues' WhatsApp group.
"On the WhatsApp group, the last move there was Hazard's farewell,' Emerson told ESPN Brazil.
"He said goodbye to the boys and such, since then, we don't know anything else. It's weird.
"He sent a 'thank you, I love you guys', and then it showed "Eden Hazard left the group".
"I said damn, he really left."