Mjekevu earned a number of call-ups to junior South African sides. He was selected in a South African Under-18 Elite Squad in 2008 and subsequently selected in the final South African Schools squad in the same year. In 2009, he was included in a South African Under-18 High Performance Squad and he was a member of the South Africa Under-20 team that played in the 2010 and 2011 IRB Junior World Championships.