Carelse was born in Somerset West. He attended and played rugby for Hottentots Holland High School, captaining their first team in 2013. He was selected to represent at the Under-18 Academy Week in the same year, kicking four conversions in his three matches. In 2014, he was a member of the squad that participated in the 2014 Under-19 Provincial Championship. He appeared in ten of their twelve matches during the regular season, scoring one try against the Golden Lions and a brace in their 43–24 victory over the Leopards as Western Province finished in third place on the log to qualify for the title play-offs. Carelse was an unused replacement in their 29–22 victory over the Free State in the semi-finals, but came on as a replacement in the final, helping his team win the title by beating the s 33–26 in Cape Town.
Carelse moved to fellow Western Cape side for the 2015 season. He was catapulted into their senior team that participated in the Currie Cup qualification series. He was named on the bench for their opening match of the season, a 32–22 victory over the in Malmesbury, but made his first class debut a week later, coming on as a replacement in their 17–48 defeat to in Kimberley. In his second replacement appearance a week later against the, Carelse scored his first try in first class rugby, scoring four minutes from the end in a 15–22 defeat. In his next appearance, a week later against the, he scored his first points with the boot, kicking a penalty in the final minute of the match to secure a 28-all draw for his team. He was promoted to the starting lineupfor the first time for their next match against the, scoring a try and a drop goal in a 29–16 victory, and also started their final match, a 17–61 defeat to the in Potchefstroom. The Boland Cavaliers won just two of their matches during the series to see them finish in fourth position, failing to qualify for the 2015 Currie Cup Premier Division, instead progressing to the First Division. After starting two matches for the team in Group B of the 2015 Under-21 Provincial Championship, he returned to the first team, making two starts and two appearances as a replacement in the Currie Cup First Division. The team had a poor season, losing all five matches, and Carelse failed to score any points for the side. He returned to the Under-21 team for their final match of the regular season, converting seven of his side's fifteen tries in a 101–19 victory over to finish secure top spot on the log. However, despite having home advantage in the semi-finals, they lost 15–19 to an SWD team that finished fourth on the log to be eliminated from the competition. Carelse established himself as the Boland Cavaliers' first choice fly-half for the 2016 Currie Cup qualification competition, appearing in all fourteen of their matches and starting ten of those. He scored a single try during the competition in a 37–25 victory over a and contributed points with the boot in matches against and the. It proved to be a successful campaign under new head coachBrent Janse van Rensburg, with Boland finishing in third position in the competition to qualify for the Premier Division for the first time since 2009. He made his debut at that level in their opening match of the season, a 16–44 defeat to the in Wellington.
