The "grassroots" comment was the clincher for me. He said he had spoken to "Garry" a number of times, and obviously Garry has done a good job selling him on the project and it's historical-grassroots aspect (which Cookie is pushing).
Would ANYONE describe Chelsea as "grassroots". No.
The remarks about Corinthians and West Ham are clearly meant to indicate the type of person Tevez is, and what floats his boat. He's won two PL medals and one CL: what personal ambition, what emotional satisfaction, would Tevez derive from being a maybe at Chelsea?