The depth of the Sharks and the discipline of the Waikato Chiefs will be under scrutiny as the Super 15 heavyweights begin to sort themselves out. Photo by Steve Haag/Gallo Images

Wellington – The depth of the Sharks and the discipline of the Waikato Chiefs will be under scrutiny as the Super 15 heavyweights begin to sort themselves out this weekend.

The NSW Waratahs, who complete the top three, will also be under pressure to maintain their unbeaten record when they face the ACT Brumbies in a tantalising Australian derby.

The Queensland Reds will test speculation about a possible lack of depth in the table-topping Sharks when they clash in Durban.

Sharks' coach Jake White will pit his bruising forward pack against the smaller, lighter Reds who will be intent on running the heavyweights into submission.

When the Golden Lions threatened the Sharks with two late tries last week, White admitted he made substitutions too early and if the Reds have the freedom to play at the pace they want he may have to take the same gamble again.

The Western Stormers have set a feisty tone for their clash against the Chiefs in Hamilton with accusations the defending champs are cheats and with a veiled threat they will react if referee Craig Joubert doesn't take action.

The Chiefs are said to be guilty of holding players off the ball at ruck time and “either the ref needs to do something about it or we (players) need to do something about it, and then it can get messy,” warned Stormers captain Jean de Villiers.

The Chiefs acknowledge a discipline problem and would have lost their first round match had not the Canterbury Crusaders missed seven penalty shots at goal.

With two bonus point wins from two outings, Waratahs coach Michael Cheika has the confidence not to tinker with his side to play the Brumbies with the only change being the return of skipper Dave Dennis from injury.

“I think they have played well enough to deserve more opportunities,” Cheika said of his line up, although the Brumbies head the Waratahs in all statistics this year except tries scored.

Like the Sharks and Reds, Saturday night's clash in Canberra also offers contrasting styles with the Brumbies game built on a kick and contain plan while the Waratahs prefer to keep the ball in hand.

The Lions, spoilt for choice at fly-half with prolific scorer Marnitz Boshoff and the fit again Springbok Elton Jantjies, have home-crowd advantage in Johannesburg for the match against the mis-firing Auckland Blues.

It has been a confident return to the competition for the Lions who have so far beaten the Stormers and Cheetahs while the Blues sole win has been against the Crusaders who are in Melbourne to play the Rebels on Friday.

After much tinkering in the backline, which produced only one win from three matches the Crusaders have moved to a more familiar look.

The 10 jersey has gone to former All Black pivot Colin Slade, internationals Tom Taylor and Ryan Crotty are paired in the midfield and All Black Israel Dagg returns to fullback.

The Rebels have shored up their backline with the return of Tom English on the left wing, with Lachlan Mitchell named on the right wing while in the front row Toby Smith gets a start along with Laurie Weeks.

The Otago Highlanders who lie second in the New Zealand conference come off a bye to play the Force who are looking to back up from their powerful win over the Rebels last week.

In the remaining fixture, the bottom of the table Wellington Hurricanes who have a sole bonus point from three matches will host the Cheetahs who have so far lost to the Rebels and Reds on their Australasian road trip. – Sapa-AFP