All Blacks and Highlanders fullback Ben Smith is likely to miss the next few weeks of Super Rugby after suffering a concussion in Friday's opening loss to the Chiefs.
The Test vice-captain rose high to contest a first-half high ball in Dunedin and banged his head on the way down, briefly knocking himself out.
Smith was then gingerly escorted down the tunnel for tests, which ruled him out for the remainder of the Highlanders' 24-15 loss.
"It looked like he hit his head on the ground and knocked himself out," new Highlanders boss Tony Brown said.
"We'll just have to wait and see how it goes, (but) probably a couple weeks."
Regarding the on-field action, Brown admitted he was frustrated with his side's profligacy, failing to cross the line despite dominating possession and territory.
But he felt his returning All Blacks regulars, including Aaron Smith, Malakai Fekitoa and Waisake Naholo, would be better for the experience.
"As a team we were just way off the pace in terms of execution," Brown said.
"Hopefully next week we can add a bit of polish."