Knee injury could sideline Springbok Mbonambi for six months
The injury forced the 32-year-old hooker to leave the field early in the World Cup final victory over New Zealand in Paris last month.
"Bongi could be out for six months," said New Zealander Plumtree after the Durban-based Sharks returned from a United Rugby Championship tour of Europe in which they lost all four games.
South Africa next play in July 2024, hosting Ireland in a two-Test series. The Irish beat the Springboks in a World Cup pool match, but lost to New Zealand in the quarter-finals.
England forward Tom Curry accused Mbonambi of making a racial slur in the World Cup semi-finals, but World Rugby found insufficient evidence and closed the case.
Further bad news for Sharks is that another Springbok two-time World Cup winner, tighthead prop Vincent Koch, will be out of action for up to three months due to a knee injury.