Silcocks started competing in athletics in 2009. At the 2009 Australian AWD Underage Championships, he earned two gold medals. At the 2010 Australian AWD Underage Championships, he earned three gold medals. He first represented Australia in 2011. At the 2011 Australian Athletics Championships, he finished first in the 1500 metre event. At the 2011 Arafura Games, he finished first in the men' 400m ambulant event with a time of 53.69 seconds. In the heat number two, two days before, he qualified third with a time of 55.80 seconds. He also finished first in the 800 metres event with a time of 2:02.95. He notched another first place win in the Men 1500m Ambulant event with a time of 4:20.87. He also competed in the 200 metre event. At the 2012 Australian athletics championships, he finished first in the men's 800m ambulant even with a time of 1:59.22 and finished first in the men's 1500m ambulant with a time of 4:05.13. He was selected to represent Australia at the 2012 Summer Paralympics in athletics. He did not medal at the 2012 Games.