Wellington - Lock Brodie Retallick joined the All Blacks' growing sick list on Tuesday ahead of the British and Irish Lions Test series after showing signs of concussion.
Retallick's Chiefs Super Rugby team left him out of the side to face the Hurricanes on Friday because he was suffering from headaches.
Chiefs coach Dave Rennie said the towering 26-year-old took a head knock in last week's win over the Waratahs, and was being left out as a precaution.
"He still had a headache yesterday(Monday), so not enough time to pass the (concussion) protocols, so he's out for the weekend," Rennie said.
He did not believe the setback would affect Retallick's prospects of joining the All Blacks against the Lions later this month.
However, Retallick has a history of concussion problems and the condition can be unpredictable.
Fellow All Black Dane Coles, the Hurricanes' captain, has been out since March with concussion and is also set to miss Friday's match.
Other All Blacks on the sick list include Kieran Read and Jerome Kaino, while Ben Smith (concussion) and Ryan Crotty (rib) were unable to finish last weekend's Crusaders-Highlanders' clash after picking up injuries.
The three-Test series between the All Blacks and Lions starts on June 24.