The Chiefs and Blues are sweating on injuries to several key players following their contrasting Super Rugby results over the weekend.

The two-time defending champion Chiefs may pay heavily for their impressive 18-10 win over the Crusaders in Christchurch on Friday.

Former All Blacks fullback Mils Muliaina exited early in his first Super Rugby match for two years following a stint in Japan.

He has re-injured an elbow which required surgery in Japan and an early diagnosis suggests he could be ruled out for some time.

Tight forwards Brodie Retallick and Ben Afeaki both failed sideline concussion tests after a sickening head clash. Both are in doubt while All Blacks lock Retallick’s neck will also be closely scrutinised.

No.8 Kane Thompson picked up an ankle injury while halfback Augustine Pulu (knee) has joined first-choice No.9 Tawera Kerr-Barlow (foot) as doubtful for Saturday’s game against the Highlanders in Hamilton.

The Blues could be weakened for Friday’s home game against the Crusaders.

Second five-eighth Francis Saili and captain/flanker Luke Braid are both nursing foot injuries, with Saili’s niggle a particular concern as All Black Ma’a Nonu is still not ready after undergoing off-season ankle surgery.

Good news for the Blues following their 29-21 loss to the Highlanders in Dunedin is that former All Blacks loose forward Jerome Kaino is free to join them this week.

Kaino’s duties in Japan ended over the weekend when his club were eliminated from contention.

The other three New Zealand teams appear to have come through week one unscathed although a cloud hangs over 39-year-old Highlanders lock Brad Thorn, who suffered a rib injury.

The only patch-up job at the Hurricanes will be to their scrum after being pushed around by the Sharks pack in their 27-9 loss at Durban.

Better goalkicking is a priority for the Crusaders after they missed seven penalties against the Chiefs.