The Lions announced that De Bruin had committed to the franchise until the end of 2021, though he will go to the World Cup as attack coach with the Boks.
Erasmus has already stated he will return to his director of rugby role within the SA Rugby structures after the global tournament, and De Bruin would have been a leading contender to replace him as head coach after guiding the Lions to the Super Rugby final last season.
The Lions have also confirmed that loose-forward Cyle Brink will be available for selection for Friday's home game with the Sharks after returning from seven months on the sidelines.
Brink tore his right patella tendon just below the knee cap during the training session with the Boks last year.
(Reporting By Nick Said; Editing by Andrew Cawthorne)
