Capewell was born and raised in Charleville, a small town in western Queensland, and played football there until the age of 17.

In Under-12s, his schoolboys team won the Queensland Foundation Cup against Murgon at ANZ Stadium in Sydney.

While attending Redcliffe State High School, Capewell played for the Australian Schoolboys in 2006.

Capewell made his National Rugby League debut on 1 June 2008 for the South Sydney Rabbitohs playing against the St George-Illawarra Dragons.

Following a season-ending shoulder injury to regular five-eighth John Sutton during Souths' campaign to make the 2010 NRL season's finals, Capewell was named to fill in the role.