Shannon started his playing career with the Northern Territory Football League's Wanderers, a club with which the Motlop family have many associations.
Having not been picked up by another AFL club and facing the prospect of an end to his time playing at the highest level of the sport, Motlop rejoined the Roosters for 2004.
He was given a second chance at the start of the following year, when Melbourne recruited him as a replacement for Troy Broadbridge, who had died during the Boxing Day tsunami.
But despite being a stalwart for the club's aligned Victorian Football League side, Sandringham Zebras, during their successful 2005 and 2006 premiership campaigns, Motlop failed to break into the first team, playing just ten times before being delisted once more at the end of his second season and returning to North Adelaide for a third spell.
Motlop has recently signed with St. Arnaud Football Club, and will play with the Saints in 2012 as they attempt to climb the ladder from a winless last position in 2011.