South African internationals Bjorn Basson and Chiliboy Ralepelle will face a judicial committee in Cape Town later this month after testing positive for a banned stimulant.
A three-man panel, appointed by the South African Rugby Union, will investigate after both players produced positive tests for the prohibited stimulant methylhexaneamine.
The tests came after world champions South Africa's game against Ireland in Dublin just over two months ago.
Basson and Ralepelle were subsequently sent home from the tour and were provisionally suspended from all rugby activities under International Rugby Board regulations until the case is resolved.
The hearing will be held on January 25.