The Stv website has a clip from the programme which is both concerning and reassuring at the same time.
The Big Bad John image has lightened a lot, the face that we saw on Setanta, unshaven and with the top button undone has been replaced with a much softer image and a different tone to his voice.
Just over three months ago big John was one of the bhoys at the Tommy Burns match enjoying a kick about with other great Celts and earning a special cheer as he lobbed the ball over Mark Brown to pull a goal back for the legends.
The Stv documentary promises to be an eye-opener and tear-jerker, it’s strange to think of someone as lively and outgoing as BBJ being anything other than larger than life.
As he says in the Stv trailer: “You worry about people who you’ll maybe leave behind.
“It spread to my lung and up to my brain, when something like this happens that’s when you can show your toughness.
“I’m not going to be able to thank everyone personally for their message but I appreciate every one, both from inside and outside football. And the biggest thanks to my fantastic family and friends.”