Two of the most slippery and mercurial scrumhalves in Super Rugby will lock horns in Sydney on Friday.

The match-up between the Bulls’ Springbok Francois Hougaard and Sarel Pretorius, the former Cheetahs try-scoring factor who has made a new home for himself at the Waratahs this season, will be one of the highlights of the encounter.

Both are attack-minded, impulsive players for whom “sniping” comes naturally,  Pretorius  knows his South African foes  so well and he will be particularly keen to remind folk in the land of his birth that he is capable of mixing it against the very best from his ex-homeland.

There is strong talk in Sydney that Pretorius will be just one beneficiary of a significant revamp to the ‘Tahs team for Friday’s fixture (11:40 SA time), following their rather blunt, muted performance in losing 23-6 to the Brumbies in Canberra last time out.

Pretorius, the 28-year-old from Reitz who was joint top try-scorer in 2011 with the Bulls’ Bjorn Basson – another player he ought to encounter in the enemy ranks this time – is  promoted off the bench at the expense of Brendan McKibbin.

The home side seek some “fuel injection” after failing to cross the whitewash against Jake White’s Brumbies, and Pretorius could play a key role in providing it.

If they have done their homework this week, they will be aware that the Bulls have had some defensive issues over the last few games, despite maintaining a good winning streak.

Certainly fielding a scrumhalf of Pretorius’s enterprise will be a good test not only of direct opponent Hougaard’s ability to police him, but also perhaps bring back into sharp focus the defensive game of No 8 Pierre Spies … many observers remain adamant that the muscular Bulls captain is well less convincing going “backwards” than he is when rampaging with ball in hand.

There can be little doubt that the exciting, eternally full-blooded Hougaard, four years rival No 9 Pretorius’s junior, has been influential in the Bulls’ status among the front-runners in Super Rugby this season, despite some fears at the end of last year that they might hit choppy waters in a “rebuilding” phase for them.

But as the international season draws closer, this is another ideal chance for him to emphasise to national coach Heyneke Meyer – still thought to be considering an ongoing Bok role for veteran Fourie du Preez – that he can match his unquestioned skill and enthusiasm levels with an ability to show calm generalship and option-taking acumen of the kind Du Preez remains so renowned for.

In what shapes up on paper, to a good extent, as a battle of Duracell bunnies at scrumhalf on Friday, Hougaard sometimes shrewdly “taking the pace off the game” or resorting at correct times to in-form halfback partner Morne Steyn to dictate matters judiciously with his boot if things get helter-skelter, may well help the Bulls tighten their defensive act and thus have an even better chance of winning their second assignment abroad.

At the same time, the Bulls’ own, impressive current efficiency as an attacking unit means that compatriot Pretorius will be under pressure to bury perceptions here, as he abandoned our shores, that he is not the most willing or able customer in the tackling department …

WARATAHS v Bulls
Friday 11 May 2012
Allianz Stadium (7.40pm)

15. Daniel Halangahu (Sydney University)
14. Tom Kingston (Sydney University)
13. Rob Horne (Southern Districts)
12. Adam Ashley-Cooper (Northern Suburbs)
11. Atieli Pakalani (Southern Districts)
10. Berrick Barnes (Sydney University), vice captain
9. Sarel Pretorius (Gordon)
8. Wycliff Palu (Manly)
7. Chris Alcock (Eastwood)
6. Rocky Elsom (Randwick), captain
5. Kane Douglas (Southern Districts)
4. Dean Mumm (Sydney University)
3. Sekope Kepu (Randwick)
2. John Ulugia (Southern Districts)
1. Benn Robinson (Eastwood)

Replacements
16. Josh Mann-Rea (Manly)
17. Jeremy Tilse (Sydney University)
18. Sitaleki Timani (Southern Districts)
19. Lopeti Timani (Southern Districts)
20. Dave Dennis (Sydney University)
21. Brendan McKibbin (Eastern Suburbs)
22. Tom Carter (Sydney University)