Highlanders scrumhalf Fumiaki Tanaka has injured his calf and will need about four weeks to recover, the reigning Super Rugby champions said Tuesday.
The Japan international sustained the injury while practicing in Auckland, and sat out the season opener against the Blues on Friday at Eden Park.
The 31-year-old, who plays for the Japan Top League's Panasonic Wild Knights, was not named to the starting lineup in the match that saw the Highlanders waste an early lead and go down 33-31 to the Blues.