South Africa stick with their back-up scrum-halves as De Klerk stays at Sale

• Siya Kolisi escapes with warning after Murrayfield incident• ‘Wales are almost the silent assassin at this stage,’ says ErasmusFaf de Klerk has played a significant role in South Africa’s revival this year, but the scrum-half will again be playing for Sale this weekend rather than lining up for his country. The Springboks have first call on him under World Rugby regulations, but they have allowed him to remain with the Sharks despite their head coach, Rassie Erasmus, stating that Wales on Saturday will be the toughest game of their four-match tour. Related: Rugby union: talking points from t…