Wagner Ribeiro said: "I met Peter Kenyon in London on Thursday.
"He told me that they were considering making an offer of £28m for Robinho. We did not talk about wages or the length of the contract."
Robinho, 24, also confirmed there was firm interest from the Blues.
He said: "What could happen is that I could go to Chelsea, as I have an offer from them. Milan are also interested in me."