In 2013, Sithole was a member of the South African Under-20 side that competed at the 2013 IRB Junior World Championship in France. After substitute appearances in their pool stage matches against the United States and England, he started in their final pool stage match against hosts France. He was an unused substitute as South Africa got eliminated from the competition in the Semi-finals against Wales, but was restored to their third place play-off match against New Zealand, helping South Africa to a third-place finish in the tournament.