The Chelsea supremo was speaking at the launch of a new sponsorship tie-up with Etihad Airways.
Ballack's absence sparked fresh speculation that the midfielder would be sold in January's transfer window, with Real Madrid favourites to land him.
But Kenyon insisted that Ballack will not be sold and declared: "We should kill that one, not just for now but for January. There has been no discussions, the decision to leave Michael out of the squad is purely medical.
"Any suggestion it is surrounding a transfer in January is equal rubbish. That is just something that is not helpful to the player or the club and we should concentrate on the facts."