He kicked 4 goals against the Kangaroos in Round 4 of 2004 in one of his best matches of his career, and was noted as a consistent rebounding backman with a strong mark.
However, a serious knee injury in Round 10, 2004 against the Western Bulldogs interrupted his career and the very slow process of recovery resulted in Jason being traded to the Carlton Football Club at the end of the 2005 season.
It was at this late stage that Saddington was told for the first time that the medical staff at Sydney Swans were aware of complications that had resulted from his first knee injury and had withheld this information from him and also from his new club.
With the replacement of coach Denis Pagan with Brett Ratten, Saddington spent more time as a part-time forward later in the season.
In 2012, Saddington played for the Balmain Dockers in the Sydney AFL competition alongside premiership players Nick Davis and Chad Fletcher.