 Totton and Welling, Cargill signed his first professional contract on a one-year contract in April 2013.After making an impressive display in the pre-season friendly and his loan spell at Welling at the first half of the 2013–14 season, Cargill signed a two-year and a half contract, keeping him until 2016.In effort of making a first team breakthrough ahead of the 2014–15 season, Cargill made his first senior appearance for Bournemouth on 12 August 2014 as a centre-back in a 2–0 League Cup win at Exeter City, and seven days later, on 19 August 2014, he was rewarded with a place on the bench in Bournemouth's 2–1 defeat to Nottingham Forest in the Championship.