De Bruin got recognised for provincial selection at primary school level in 2006, when he was included in the Under-13 squad that played at the Craven Week competition. In 2009, he was selected in their Under-16 Grant Khomo Week squad and he played at the Under-18 Craven Week competitions in both 2010 and 2011. After the 2011 tournament, he was included in a South African Academy side that played against a France Under-18 side in Durban. In 2012, De Bruin moved to Bloemfontein. He made eleven appearances for the side during the 2012 Under-19 Provincial Championship, starting ten of those matches. At the start of the 2013 season, he played for university side during the 2013 Varsity Cup competition, where he made six substitute appearances. He was selected in the South African Under-20 side that played in the 2013 IRB Junior World Championship in France. He started in their first two pool matches, a 97–0 victory over the United States and a 31–24 victory over eventual champions England. He didn't feature in their match against hosts France, but was restored to the starting line-up in their semi-final clash with Wales, where South Africa suffered an 18–17 defeat. He was also in the run-on side that met New Zealand in the third-placed play-off and De Bruin scored one of six South African tries as they beat New Zealand 41–34 to secure a third-place finish in the tournament. In the latter half of the 2013 season, De Bruin played in four matches for the side during the 2013 Under-21 Provincial Championship before he played in another Varsity Cup campaign for the in February and March 2014.
De Bruin's first taste of senior provincial rugby came during the 2014 Vodacom Cup competition for the after the 2014 Varsity Cup concluded. He made his debut when he was named in the run-on side for their match against the in Cradock, helping his side to a 31–3 victory. That was the first of five consecutive starts De Bruin made during the competition as they reached the quarter-finals, where they were knocked out by his former side, the. De Bruin was included on the reserve bench for the ' second-last match of the 2014 Super Rugby season against the in Bloemfontein. In July 2014, De Bruin signed a new contract with the until the end of 2016.
