Chiefs coach Dave Rennie will have words with SANZAR over what he feels was a poorly managed incident during last weekend's loss to the Rebels.

Prop Ben Tameifuna was cleared by the team’s doctor after a head knock, but taken off the field by the independent match doctor for further assessment.

The Chiefs were denied the chance to bring on a replacement as the match continued, during which time the Rebels crossed over for a crucial try.

Rennie says something has to change.

Meanwhile, the Blues have confirmed captain Jerome Kaino is out for at least the next five weeks after a finger injury.

This Friday, the Crusaders will play the Reds at 7.35pm while the Rebels will face the Blues at 9.40pm.