An athletic ruckman in his playing days with Hawthorn from 1950-59, he won four best and fairest awards and captained the club for five seasons.
Yet he is very modest when speaking about that time.
"My friends say that they saw me play and it wasn't a pretty sight," the 85-year old Hawthorn icon says in the second instalment of AFL Media's four-part series on the Kennedy clan.
"That's about the best description I can give you, and I understand what they mean."
Kennedy snr later achieved fame by coaching the Hawks to their first three VFL premierships – in 1961, 1971 and 1976 – turning Hawthorn from a laughing stock into one of the most respected and successful clubs of the modern era.
But on Saturday he'll battle mixed emotions as his grandson, Josh, attempts to help the Swans defeat Hawthorn in a Grand Final for the second time in three years.
Part one of The Kennedy series focuses on Josh's decision to leave the Hawks and join the Swans; part three (published Thursday), looks at the role John jnr played in four premierships for Hawthorn, and the last instalment (Friday) captures the family bonds.
The Kennedys was produced by AFL Media filmmakers Peter Dickson and Shaun Vance.
