New Highlanders co-captain Ash Dixon's Super Rugby preparations have been set back by at least a month after he injured his back last week.
Coach Tony Brown said Dixon, who was injured in a training drill and taken to hospital last Thursday, is waiting to see a specialist.
Brown said 28-year-old Dixon had lost feeling in his legs for five to 10 minutes, but was now back walking.
North Harbour hooker Adrian Smith has come into the Highlanders squad as cover for Dixon.
Brown, in his first year at the helm of the Highlanders, had appointed Dixon and All Blacks fullback Ben Smith as co-captains, but won't be naming a replacement skipper in Dixon's absence.
No.8 Luke Whitelock will captain the Highlanders in their opening pre-season game against the Crusaders in Darfield on Saturday.
Brown has named a team missing all his first-choice All Blacks, who only returned to training this week.
The Highlanders will also contest the Brisbane Global Tens next week before completing their pre-season against the Waratahs in Sydney on February 16.
