The world's best hooker is now under a concussion cloud.

Hurricanes coach Chris Boyd revealed today at the team naming media session that Dane Coles is actually battling concussion-like symptoms as well as the dodgy calf that has been advanced as the cause, in recent weeks, of his prolonged absence.

The Highlanders match on March 18 was Coles' last outing. He had a knee injury before the calf became an issue. A review of the Highlanders match DVD revealed no apparent head knock.

"Colesy's situation is complicated by the fact that... subsequent to his knee injury, he not only developed a calf strain but also some headaches. He is now under a return to play protocol for concussion. The source of that is completely unknown to us," Boyd says.


They cannot load his calf as he is getting headaches when he ups his heart rate and intensity at training. So any return date for Coles is unknown until he clears those symptoms.

Boyd was not 100 percent certain but did not know of any history of concussion with his hooker.

"There's no smoke and daggers stuff. At the end of the day, he has started to return to train and developed some headaches," Boyd says. "It's not normal, but if you look at it in context, because of his knee injury, the first part of his rehab was no training at all so, if there were symptoms post the game that would come out under exercise, they were not apparent."

Ardie Savea, who has moved back to No 8 for Friday night's match against the Stormers was disappointed for his teammate.

"As a team, we knew he had a knee or calf injury, but we (only recently) found out about this. There is a protocol to go through, so we just wish him all the best. Concussion is worrying, but I'm not too sure how serious this is. You would have to speak to the doctor about it," says Savea.

The Coles news is the last thing All Blacks coach Steve Hansen wants to hear just days after his captain Kieran Read needed a thumb operation. The Lions tour kicks off in exactly a month.