THE semi-final bound Waratahs will this week be forced to defend their reputation as the "derby kings" of Australian rugby when they meet the Reds in Brisbane.

The Waratahs face a short turn-around to prepare for the round 14 encounter on Saturday night, and will have to do more than deal with the hyped-up Queenslanders.

The fatigue resulting from two bruising games against the Stormers (whom they played in Cape Town this morning, Sydney time) and the Bulls in Pretoria last Saturday will play a role.

On top of that they need to contend with the inevitable jet leg, and the knowledge that the game will play an integral role in the Waratahs' semi-finals future.

However, Tahs defence coach Les Kiss believes the side's pride in its impeccable record in local derbies during the five-year tenure of head coach Ewen McKenzie will reinforce their will to win.

The Waratahs have faced plenty of scrutiny in recent years - much of it critical until the last few weeks. What has slipped below the radar, though, is that NSW have lost only two and drawn one of 14 games against Australian sides since McKenzie took over from Bob Dwyer in 2004.

With McKenzie leaving NSW at season's end - he and French club Stade Francais have agreed to terms - his side is keen for him to bow out with a final derby success.

"One great legacy Ewen will leave is the legacy the Waratahs have built in their standing in Australian rugby in terms of the derbies," Kiss said.

"We have dominated them all over the last four or five years.

"'Derby kings' is a good way to put it. It is something Ewen is fiercely proud of. We are all fiercely proud."

Kiss, whose own future with the Waratahs is up in the air after NSW Rugby deferred appointing a new coach until after the Super 14, believes the signs are there that the dominance will continue.

Saturday's game against the Reds, in which several Waratahs, including Dan Vickerman and David Lyons, will play their last derby before heading overseas, could even signify a changing of the guard.

But Kiss says the ability of the Waratahs to fend off their traditional foes now hinges on self-belief.

"Queensland was one of the teams that was really important to us," Kiss said. "We have been able to get those initial results that we wanted.

"One of the other key issues is that we have a lot of young guys who are stepping in and don't have a history of what it was like when Queensland used to always beat us.

"They are part of the generation where NSW beat Queensland and we are keen to keep that going."