Australian Super Rugby conference leaders the Brumbies have had a dominant scrum in recent weeks but it will be heavily tested by the Blues in Canberra this weekend.
The Brumbies' pack have earned two penalty tries from overwhelming their opposing forwards in recent weeks but will scrum against the All Blacks' most-capped prop, loosehead Tony Woodcock, and a huge Blues front eight in Canberra on Friday.
The Brumbies can narrow the six-point gap to Super 15 leaders Coastal Sharks with victory over the Blues, with the South Africans having a bye this weekend.
The front row has been one of the Brumbies' strengths but it will be missing Wallabies hooker Stephen Moore as he will miss his first Brumbies game through injury since 2011 after being given a week to recover from a niggling knee concern.
With Moore and the 61-Test capped Ben Alexander, the Brumbies have an almost 90 percent scrum success rate this campaign.
The Blues have had the worst performing scrum with a 67 percent success rate, but Alexander is respectful of Woodcock's experience.
"If you want to talk about consistency, (Woodcock's) been consistent over a long time and the scrum laws have changed a lot over that time," Alexander said, while admitting that some elements of the new scrums laws introduced this year may have worked in the Brumbies' favour.
"The hit's been taken out of it. I don't think we were really ever trying to get a big hit. So maybe that's benefited us," he said.
The Brumbies, under first-season coach Stephen Larkham, have won four of their six games but historically strike trouble with the Blues in Canberra.
The Blues, who will have All Blacks blindside flanker Jerome Kaino back as team captain, have the added incentive of taking over at the top of the New Zealand conference if the Chiefs falter in South Africa this weekend.
The Chiefs are expecting their suspect lineout to be tested by the Cheetahs in Bloemfontein on Saturday.
The defending champions' main weakness was exploited in the 34-34 draw with the Bulls in Pretoria last weekend and Chiefs forwards coach Tom Coventry expects it will again be tested against the Cheetahs.
"It's a big part of their game," Coventry said.
"They grow up with it (in South Africa). There are technical issues that we need to look at that are going to make us better at stopping it. A lot of it is attitude but it's a difficult thing to stop once it gets going," Coventry said.
It's been a rocky few weeks for the Chiefs. They were upset 18-15 by Western Force on the way over to South Africa and last weekend they needed a stoppage-time touchline conversion to snatch a draw with the Bulls.
But the Chiefs have a good record in Bloemfontein, winning two and drawing another in their four meetings.
The fourth-placed Lions have the seven-time Super Rugby champions the Crusaders in Johannesburg on Saturday.
The Lions, promoted back into Super Rugby this year, have been one of the surprises with a 4-2 record, while the Crusaders have struggled and are 2-3, leaving them bottom of the New Zealand conference.
Regular captain Flip van der Merwe is fit again and back to lead the Bulls against the Hurricanes in Napier on Saturday.
The 67-cap lock takes over the captaincy and number five jersey from Victor Matfield, who will only play on the Australasian tour if there is an injury to the other locks, coach Frans Ludeke said.
In this weekend's other games, the Highlanders host the Rebels and the Reds are at home to the Western Force.