Glasgow man Kean speaks fluent Portuguese after playing and coaching in Portugal and is seen as an ideal man to work with new Chelsea boss Luis Phillipe Scolari.
Kean had also coached at Reading and Fulham where he met up with Chris Coleman.
However, Kean has rerjected Chelsea's offer, telling the cllub website: "There was someone acting on Scolari's behalf. I was very honest about it and said that I'm under contract at Coventry City in a very exciting
project."