Luke Braid has been knocked out twice already this season and is heading for a two-week rest.
As New Zealand Rugby continues to get to grips with many high-profile concussion incidents this season, Braid's most recent happened in the second half of the Blues' 16-14 win over the Brumbies when he made a tackle in what initially looked an innocuous collision. He was taken off straight away.
His first occurred in the loss to the Hurricanes in Palmerston North when he was kneed in the head by lock James Broadhurst in an act of foul play. Braid was taken off straight off the field and didn't miss a game as the Blues' had a bye the next weekend but now he is likely to have a fortnight off, meaning he will miss not only Saturday's match against the Highlanders but also the next one against the Crusaders in Christchurch.
Jerome Kaino, Tony Woodcock and Josh Bekhuis have also been concussion casualties at the Blues this season, with Highlanders' prop Josh Hohneck serving to put the issue higher on New Zealand Rugby's priority list after he played on despite being knocked out against the Crusaders last weekend.
The organisation will continue a trial in Saturday's match between the Hurricanes and Waratahs in Wellington whereby the match doctor will be given a television in order to check for signs of concussion injuries after collisions.
The issue has led to some commentators noting that coaches should take more of a responsibility given they have more access to game footage than anyone else, but Blues coach John Kirwan said doctors were still the best placed to make the decision on whether to withdraw a player or not.
"There are screens everywhere so our doctor sees that stuff and our doctor has responsibility for everything," he said. "If we notice something afterwards and he [player] has passed his [concussion] test then we need to say we think he's off his game by five per cent and we need to re-assess it. I think the grey area is when they pass their test and they go back on... I think if someone is knocked out and we can all see it, that's the test, I believe."
In Kaino's case he was clearly dazed in the match against the Lions but passed a test and played on after doctor Stephen Kara was unsighted and didn't see the loose forward stagger. Kara later told the Herald if he had seen Kaino's reaction he would have taken him off straight away.
However, Kirwan was in no doubt as to the best course of action. "It's a doctor issue and we need consistency around a whole lot of things with Sanzar at the moment. We need to get some consistency on the ruling on concussion."