Rugby: Concussions real headache for Rennie

Their form remains a concern but the number of Chiefs ruled out through concussion represents an additional headache for Dave Rennie.

Friday's defeat to the Brumbies saw the defending champions' slump extend to one win from six and resulted in three more members of their squad being subjected to sideline concussion testing.

While Mahonri Schwalger was the only player who failed to return to the field, the head knocks continued a worrying trend for the champs, one that has seen their medical ward requiring a revolving door.

Three players were missing from the squad that flew to Canberra due to concussion protocols, part of an 11-strong injury list that has hampered the Chiefs' much-vaunted depth throughout the campaign.

Little can be done to avoid such a glut of head injuries but the level of misfortune must leave Rennie wondering exactly whom he has angered.

"It's just bad luck," he said. "It's a collision sport - it happens - and our game gets more and more intense every year."

Indeed, with athletes getting bigger, faster and stronger, the violence in those collisions has only increased, meaning players are as susceptible to friendly fire as opposition hits.

"Liam Squire ran into a shoulder, Tawera [Kerr-Barlow] was making a desperate tackle and got his head in the wrong position (both last week), Ben Afeaki and Brodie [Retallick] clashed heads making a tackle (in week one)," Rennie said. "It's just a bit of bad luck."

Compounding that luck is the stringent testing in today's game. A necessity to ensure the players' long-term health, such protocols were conspicuous by their absence in a bygone era.

"There are a lot more precautions around it now and anyone with the slightest issue is generally taken off and assessed," Rennie said. "Maybe in my day, when I was playing, guys just stayed out there because we didn't know any better."

There is light at the end of the tunnel for the Chiefs, with Kerr-Barlow and Squire both set to return this weekend. Elsewhere, James Lowe featured for the first time in a month against the Brumbies and Charlie Ngatai, missing since March, is on the verge of a comeback.

"Over the last few weeks we've had guys coming back in - you get two or three back but you lose two or three," Rennie said. "It's kind of a revolving door but hopefully we're starting to get numbers back."

Watch: Rugby Highlights: Brumbies 41 Chiefs 23

One of those numbers would be a particularly useful addition. As he showed in the first 40 minutes against the Brumbies, Schwalger steadied the Chiefs' shaky lineout and solidified the scrum - two areas of opposition strength - before being forced from the field.

Rennie was impressed with the impact of Super Rugby rookie Nathan Harris after he stepped into Schwalger's shoes, but the coach acknowledged the importance of the veteran: "In the lineout, we've battled a bit, but Moe's experienced. He's a very good thrower and a very good scrummager."

If the champs' set piece can continue to make gains, it will leave an inconsistent attack as the chief area of focus for the brains trust. Four tries in three games is well short of regular pace for last season's leading scorers and Rennie was aware of what is causing the problem.

"We're making too many errors and they just don't allow you to build and apply pressure.

"We've dug ourselves into a bit of a hole but, having said all that, we're only one point behind the leader in our conference.

"So our fate's in our own hands but we need to get things going against the Lions this weekend."

Hard knock life

Ben Afeaki - concussion
Aaron Cruden - thumb
Hika Elliott - neck (out for season)
Robbie Fruean - heart
Tawera Kerr-Barlow - concussion
Tanerau Latimer - Achilles
Mils Muliaina - elbow (out for season)
Charlie Ngatai - calf
Robbie Robinson - hip (out for season)
Liam Squire - concussion
Kane Thompson - hamstring
Another one bites the dust:
Mahonri Schwalger - (concussion)