The 25-year-old suffered the injury just seven minutes into his first appearance for Munster in their Pro14 27-25 defeat by Leinster on Saturday.
“It has been confirmed that the province’s newest debutant, RG Snyman, sustained an ACL (anterior cruciate ligament) tear in the opening minutes of Saturday night’s Pro14 encounter against Leinster,” read Munster’s statement.
“The lock will meet with the specialist next to discuss surgery and management.”
The 23-times capped Snyman, a towering presence at 2.05 metres (6ft 9in), featured in every game of South Africa’s successful World Cup campaign.
Snyman, who signed on a two-year contract from Japanese outfit Honda Heat, is one of two members of the Springbok squad to join Munster with centre Damian de Allende also signing post the quadrennial showpiece.
Munster need to beat rival Irish province Connacht this weekend to secure a place in the Pro14 semi-finals.