Inside centre De Villiers suffered career-threatening knee ligament damage during a test defeat by Wales last November.
Flanker Burger was recovering from injury three seasons back when he developed bacterial meningitis and doctors told his parents they feared the worst.
But when the South African national team bade farewell to supporters at a Johannesburg hotel this weekend before flying to London, De Villiers and Burger made passionate vows.
"We will never give up," promised a deeply emotional De Villiers, 34, as he spoke from a temporary outdoor stage.
"The time to play rugby has come and we are ready," stressed Burger, 32, whose father was also a Springbok forward.
But behind the selfies, smiles, hugs, waves and seemingly endless signing of autographs, lay tales of remarkable determination by De Villiers and Burger to be part of the greatest rugby show.
