WELLINGTON (Reuters) - One test All Blacks centre Charlie Ngatai is still suffering from concussion symptoms with no timetable set for his return, Waikato Chiefs coach Dave Rennie said on Tuesday.
The 26-year-old has been sidelined since last May when he suffered a head knock in the Chiefs Super Rugby match against the Otago Highlanders.
The injury cost Ngatai his place in the All Blacks last year. He had been named in Steve Hansen's squad for their June internationals against Wales but then released to continue his rehabilitation.
"He's had a few setbacks over the last period of time and there's a bit of light at the end of the tunnel, but we're not going to rush that," Rennie told reporters in Hamilton on Tuesday.
"What tends to happen if you push things a little bit too much you go backwards a bit. So its been a frustrating time for him."
Rennie said Ngatai was not back in full training but was "starting to ramp things up a bit" and it was too early to consider looking for a replacement in the squad.
"He got the knock in May, so it's a hell of a long time ago," he added. "Richie McCaw went through this, where he was out for a 12-month period, so his health is the most important here, so we're not going to rush it.
"With Tim Nanai-Williams back, he can cover midfield, we've got Anton (Lienert-Brown) and Johnny Fa'auli, and Beaver (Steven Donald) has played a bit of 12 in Japan recently, so we've got other options."
The Chiefs first match of the new season is against the Highlanders in Dunedin on Feb. 24.
Ngatai joins Wellington Hurricanes lock James Broadhurst as All Blacks players still battling long-term effects of concussion.
Broadhurst, who made his test debut against South Africa in July 2015, suffered two head knocks in a provincial game the following month and has not played since.
The Hurricanes said in December they had released him to continue his rehabilitation away from the team, though he is still contracted to the side for 2017.