When Kosar's co-commentator mentioned that Clemens had recently met the pope, he said, "Bless me father for I have sinned. I have to watch him the whole fourth quarter" before going on to criticise the Rams' receivers and receivers coach.
Clemens acknowledged that Kosar serves as a good example as far as his on-field achievements are concerned, but believes that he has also shown examples of what not to do as a commentator.
"He gave us a lot of great examples throughout his career of what it's like to play quarterback, and how to do it at a high level," Clemens told the St Louis Dispatch.
"Unfortunately, he also gave us a couple of examples in his commentating career of what not to do."
Kosar's comments have also been condemned by the Browns, who branded them "personal and unprofessional".