As per Allen Donald, spinners will be key in the Durban Test. Provincial teams here often field three spinners. Sri Lanka won the last Test here in 2019.
https://www.espncricinfo.com/series/...full-scorecard
The stage is set for Simon Harmer to return playing for SA. Harmer played 5 Tests for SA back in 2015, including a two Test tour to Bangladesh. He then left SA to play as a Kolpak player in English County. Now that Kolpak deals are gone due to Brexit, he's back to play for SA (along with pacer Duanne Olivier).
Harmer is renowned as an attacking offspinner and was the top wicket taker in FC cricket worldwide last year:
https://stats.espncricinfo.com/ci/en...2021;type=year