As a scholar at Maritzburg College, Kriel was selected in the squad for the Under–18 Craven Week tournament, where his performance earned him an inclusion in the South African Schools side in 2012. He started in matches against France, and England and was an unused substitute against Wales in the three-match series played in August 2012. After finishing school, Kriel – along with twin brotherDan – made the move to Pretoria to join the prior to the 2013 season. Despite not initially being named in the South Africa Under-20 squad for the 2013 IRB Junior World Championship, a hamstring injury suffered by Sergeal Petersen led to Kriel's inclusion into the squad. Kriel appeared as a substitute in their first match of the competition and scored two tries in a comprehensive 97–0 victory over the United States. Further substitute appearances followed against England and France. He was an unused substitute in their semi-final match against Wales, before making his first start of the competition in the third-placed play-off match against New Zealand. For the remainder of 2013, Kriel played more youth rugby for the Blue Bulls, scoring 42 points in ten matches to help the win the 2013 Under-19 Provincial Championship competition and also making three appearances for the side. He was included in the South Africa Under-20 side for the 2014 IRB Junior World Championship, and also named one of two vice-captains for the tournament.
Senior career
In 2014, Kriel was included in the training squad prior to the 2014 Super Rugby season, but failed to make any matchday squads, instead playing for the in the 2014 Vodacom Cup competition. His first class debut came on 8 March 2014 against in Pretoria and he scored his first senior try just a week later, in their match against the. In June 2015, he extended his contract at the Bulls until October 2018, which was extended even more until October 2019 just two months later following Kriel's call-up to the South Africa squad.
South Africa
In June 2015, Kriel was named in an extended South Africa squad prior to the 2015 Rugby Championship. He started for South Africa in a warm-up match against a World XV, helping them to a 46–10 win. He was named in the squad for their opening Rugby Championship match against and was named as the starting centre for the match to become Springbok Number 867. Not only was this match Kriel's test debut, but he also scored his first test try in the 44th minute of the match. However, he ended the match on the losing side, with a late Tevita Kuridrani try securing a 24–20 victory for Australia. Kriel was named in South Africa's squad for the 2019 Rugby World Cup. However he had to withdraw through injury in the pool stage and was replaced by Damian Willemse. South Africa went on to win the tournament, defeating England in the final.
