Kolisi a major World Cup worry for Springboks

A knee injury has ruled South Africa captain Siya Kolisi out of the rest of the Super Rugby season and threatened his participation in the build-up to the World Cup later this year.

Kolisi went off towards the end of the first half of last Saturday's 34-22 home win over the Otago Highlanders, but coach Robbie Fleck said afterwards he did not think the injury too significant.

However, Kolisi is out of the Stormers' team to play away against the Lions in Johannesburg on Saturday and told local reporters he will miss the rest of the campaign.

"I'm going to be in the brace for six weeks‚ which is the alternative to surgery‚" he told Timeslive.

"I'm hoping to be ready to play in time for the Rugby Championships."

South Africa host Australia at Ellis Park in Johannesburg on July 20 in the opening game of this year's Rugby Championship - after the conclusion of the Super Rugby season.

The Stormers must also do without Springbok lock Peter- Steph du Toit, whose shoulder injury keeps him sidelined for the next three weeks.

The two injuries are a major blow to the Cape Town team's hopes of making the June playoffs. They are in a tight battle for the leadership of the South African conference.