While Avondale have dominated the competition in recent times, the Tahs have been on a slow build after a number of lean years.

That build has Tech tracking on an upward trajectory, with the side taking plenty of confidence out of last week's convincing 41-12 win over Camden.

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Olsen, however, recognises Saturday will be a far bigger challenge.

"There's no bigger test than playing Avondale," Olsen said. "We got the result last week, but like everybody we were pretty rusty. With no trial games and a shorter build up, everybody's in the same position.

"We've done a lot of work recruiting in the off-season and we've been able to keep most of those guys through this period. They're chomping at the bit to play.

"We're excited for the opportunity to take on the current premiers. They've been the epitome of consistency over the last decade, they hardly ever lose a game. We've got to be on our game if we want to compete with them."

The rain has cast a cloud of uncertainty over the match, with Saunders Oval closed. The game has been shifted to Gerry Capetta Oval, with a final decision to be made after a ground inspection on Saturday morning.

Avondale were impressive, though not perfect, in last week's come-from-behind win over Shamrocks, the Wombats scoring three late tries to prevail 45-34.

Olsen recognises the Tahs will start Saturday's clash as outsiders, but he has spent the week preparing his side for a big defensive effort.

The coach has been impressed with the effort at training and he's confident Tech can pull off the upset if they arrive at the ground with the right attitude.

"You've got to make sure your defence is intact against a good side like Avondale. They can score plenty of points, so you've got to play for the full 80 minutes.

"There are times in the game where they will have the ascendency, it's unrealistic to think you'll keep them to zero. But you need to minimise the effectiveness they have, try control possession and control the game."

Tech's clash with Avondale comes as the Illawarra Rugby board opted against adding finals to this year's season.

Instead, it remains a nine-round competition with the team sitting on top of the ladder declared the champions.

Olsen was disappointed finals were not incorporated into the season and he hopes it's a decision that can be reassessed in the coming weeks.

"I'm hopeful the conversation can be revisited once a few more games are played and the clubs can see that finals are beneficial for everybody involved. It's not just the players, but the supporters as well.

"It is challenging and there are limitations, but I don't think 'it's too hard' is an adequate response. It should be trying to find a way to make it happen, not just say 'too hard' and throw your hands in the air."

Saturday's other matches will see Kiama host rivals Vikings, while Shamrocks will look to rebound from last week's loss when they face Campbelltown.

Finally, Camden will make the trip down to Shoalhaven.