Merson wrote in the Daily Star Sunday: "What they are doing to him is disrespectful.
"He is one of the best midfielders of the modern age, a goalscoring phenomenon who has given everything for that club.
"To try and force him out like this is an absolute joke. I think he will go in January – and I’m shocked by that.
"Chelsea must be mad to let him go. They are already short in midfield, and things will soon get worse.
"John Obi Mikel is going to the African Nations Cup with Nigeria, and Oriol Romeu is already injured.
"If you’re Chelsea, I just don’t see how you fail to keep Lampard. It’s ridiculous. He has been such a big part of that club."