South Africa prop Trevor Nyakane has been replaced by Thomas du Toit in the Springboks squad after tearing his right calf muscle in their opening defeat to New Zealand, the team said on Monday.

Nyakane was seen with his head in his hands pitchside after limping off in the final minutes of Saturday's 23-13 Pool B reverse in Yokohama.

"It's very tough on Trevor," said coach Rassie Erasmus. "He has had a great season and added value whenever he took the field.

"It's a blow to him and the team, but it's also an opportunity for Thomas and for Vincent (Koch, another squad member) who now have the chance to step up."

Du Toit, who has been on short-term loan at Toulouse, was due to arrive from France on Tuesday. The Springboks' second game is against Namibia in Nagoya on Saturday.