IAN RANSOM WORLD champions South Africa will not take part in the Rugby Championship in a decision that leaves the tournament greatly diminished two weeks before kick-off and southern hemisphere rugby facing an uncertain future. South African Rugby said on Friday "player welfare" concerns and logistical difficulties left them no choice but to pull the defending champions out of the competition which also features Australia, New Zealand and Argentina. "It seems impossible that the Springboks won't play a test match in 2020, but public health and safety have been the primary concern and we have been collateral damage like so…