Playing for the Black Leopards and being relegated from the 2020-21 South African Premier Division,[2] Mthethwa was signed by first-tier team Stellenbosch in the winter of 2022.
Only three Stellenbosch players had been called up before, these being Athenkosi Mcaba, Antonio van Wyk and Jayden Adams.
[1] Nearing the end of the season, several clubs were linked with buying Mthethwa, including Kaizer Chiefs[7] and AmaZulu.
[8] Stellenbosch manager Steve Barker was reluctant to sell to a South African club, but was "not going to stand in the way when a European team comes in for one of our players, and he's got an opportunity to play at a higher level".
[7] On 21 September 2023, with just two days remaining of the transfer window, Mthethwa signed for Kaizer Chiefs on a three-year deal.