The Monty Python stars continue to see each other following Jones' dementia diagnosis, which left him unable to communicate.
Sir Michael is now concerned that his long-time friend and co-star does not know who he is.
Speaking to the Daily Express, he said: The last time I saw him I don't think he recognised me.
"We knew each other well. It feels like a part of yourself isn't there any more."
In 2015, the Monty Python writer, director and actor was diagnosed with a form of dementia which affected his ability to communicate.
Sir Michael has said that despite the degeneration, his friend still finds moments of joy.
He said of his last visit: "At a certain moment Terry began to really laugh, the way he used to laugh. That was a great moment.