Toulouse - Flanker Jerome Kaino will be out "two to three weeks", Toulouse assistant coach Regis Sonnes said on Wednesday.
The 35-year-old New Zealander has just taken over as club captain in place of hooker Julien Marchand, who suffered a season-ending injury playing for France as they lost to Wales in the opening round of the Six Nations.
Kaino, a World Cup winner in 2011 and 2015, was forced off with 10 minutes left as Toulouse beat Racing 92 on Sunday to stretch their unbeaten run in the Top 14 to 10 games.
"It's nothing serious, but he needs treatment, it will take two to three weeks," said Sonnes.
Gillian Galan replaced Kaino on Sunday and will probably start at home as the league leaders take on struggling Montpellier on Saturday in the 17th round of the Top 14.
Samoan lock Joe Tekori, rested against Racing, could take over the captaincy.