Will Skelton and Tolu Latu faced the wrath of the SANZAR judiciary following the Crusaders clash © Getty Images

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Defence and discipline: they're the two "d-words" of rugby; and the balance between the two, with the required aggression, is essential for success. But it can be a fine line, one New South Wales Waratahs have crossed over the past two rounds of Super Rugby.

The Waratahs' defensive aggression was noticeable from the outset against the Crusaders last week, with forwards Tolu Latu and Will Skelton clearly given the responsibility of rattling the Kiwis' All Blacks stars. It worked in some respects as the Waratahs recovered from a first-minute try to post a memorable victory in the grand final rematch; but later that week, when Latu and Skelton faced SANZAR judicial hearings, they paid a hefty price.

Sam Warburton's dangerous tackle in the 2011 World Cup 'will serve as a reminder of how it can go horribly wrong' © Getty Images

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Michael Cheika went into the weekend fixture against the Lions in Johannesburg without Skelton and Latu after their appeals against respective two- and four-week suspensions were thrown out. And his team, at Ellis Park failed again to get the balance right. This time it was winger Rob Horne who was sin-binned for a lifting tackle, one that has since earned him a three-week spell on the sidelines. They managed to come out 10 points to the good while Latu was in the bin in Sydney, but they weren't so lucky in South Africa, Horne's tackle as well as a Jacques Potgieter's 10-minute breather, saw the Lions run up a 17-5 margin in the 20 minutes while the Waratahs were down to 14 men.

Cheika's first moves as Waratahs coach saw him build a greater physicality within the playing group, a mission that was made all the more easier with the recruitment of Potgieter. But where they found the balance between discipline and aggressive defence in their run to the title last year, the equilibrium has taken on a worrying skew over the past fortnight.

SANZAR has made clear its desire to rid the game of the lifting tackle this season, with a number of players feeling the wrath of the judiciary; it's actually a little surprising it's taken them this long. Coaches, too, have known just how detrimental the tackle can be; in this Rugby World Cup year, the memory of Sam Warburton's red card in the semi-final against France four years ago should serve as a reminder of how it can go horribly wrong.

With his Wallabies cap to come on in around six weeks, Cheika will once again call for physicality in defence. Discipline in that same defence will be key if the Wallabies are to be any sort of threat, first in the Rugby Championship and then at the World Cup in England. Skelton, Latu and Horne are all likely squad members, and they, too, must find a balance that doesn't result in their team-mates facing the world's best with only 14 men.

The trio will, however, first be sweating on their Waratahs team-mates as they face games against the Cheetahs in Bloemfontein and the Reds in Sydney before the finals season. Skelton will return from suspension in Sydney and must immediately recognise the need for a balanced approach between defence and discipline. As for Latu and Horne, their shot at redemption will come only should the Waratahs make it through to the post-season. It's likely to be a nervous few weeks.

The Waratahs discipline will be heavily scrutinised throughout the final rounds © Getty Images

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