[12] He was called into the Australian side for the second Test against India replacing an injured Alan Hurst.
[16] Gannon was dropped for the 5th Test against India and subsequent tour of West Indies in favour of Ian Callen.
According to one report, "Gannon captured 11 wickets at 32.82 in his three Tests, but most of his victims were tailenders, and the top order Indian batsmen seldom experienced difficulty against him.."[17] At the beginning of the 1978–79 season, selector Neil Harvey said Gannon was a prospect for Test selection.
[19] Gannon was elected chairman of the Western Australian Cricket Association in August 2013.
[20] Gannon was awarded the Medal of the Order of Australia (OAM) in the 2017 Queen's Birthday Honours for service to cricket.