Le Roux collided with fellow full-back Tiernan O'Halloran during an 11th-minute contest for a lofted kick and the Irishman landed heavily on his upper body and head.
The suspension prevents the Springbok playing for the Coastal Sharks against the Golden Lions in a crucial Super Rugby match in Johannesburg Saturday.
Sharks trail the Lions by seven points in the Africa 2 section with three league rounds left and must win to have a realistic chance of topping the final standings.
Le Roux was cited by commissioner James Absaloms of Kenya and Terry Willis of Australia chaired the disciplinary hearing.
South Africa won the third and final Test 19-13 in Port Elizabeth Saturday after losing 26-20 in Cape Town and winning 32-26 in Johannesburg.