Ben Smith suffered a hamstring blow in the Highlanders' 31-31 Super Rugby draw with the Chiefs that could keep him out for two months.
The New Zealand star was cleared of serious injury following a heavy collision late in Saturday's game that saw him helped off, sustaining a hamstring problem and a cut to the chin.
Smith, who will leave the Highlanders for Pau later this year, could still be out for the remainder of the Super Rugby season.
Highlanders assistant coach Glenn Delaney suggested that the All Black would miss a key stretch in the lead up to the Rugby World Cup, which gets under way in Japan in September.
"He's had a high hamstring strain so he's going to be out for six to eight weeks," Delaney told reporters. "It's just a classic rugby incident where he got caught in a tackle and overextended.
"All the right things are being done and he'll be back as quick as he can be with the right rehab."
Smith's team-mate Aaron Smith added: "Six to eight weeks, from how the injury looked, you could say, was very lucky.
"Obviously, in New Zealand rugby, we've got a few big injuries this year, but that's the game we play. [Ben Smith] is already in the mindset that he'll be back quicker than six to eight."
