Jonas, a forward, was only 17 when he made his debut in the Central District seniors in 1977.
He won his club's best and fairest in 1979 and represented South Australia in the Perth State of Origin Carnival that year.
For his performances at the carnival he was selected as an All-Australian and in doing so became the first ever Central District player to have made the team.
In 1981 he made his debut for North Melbourne and despite remaining with the club until 1988 would only play 82 games in that period due to injury.
Appointed coach of Central District in 1998, Jonas steered the club to their inaugural premiership in his third season.