The early Super League leaders head to Warrington Wolves on Thursday night looking to maintain their 100 per cent winning start.
Warrington, too, had opened impressively, but lost for the first time when falling 23-22 in Perpignan on Saturday.
One reason for that was because, at times, Catalans were able to rattle Australian stand-off Austin, the marquee signing who has made such a blistering start to life in Super League.
Few sides have managed to force him into mistakes so far, but Powell said: “He’s a good player if you let him play.
“Catalans were pretty aggressive across the whole game.
“They were really physical, carried the ball well, made him do some work defensively and got in and around him when he was catching the ball.
“So, they put him under a lot of pressure and, yes, he came up with some errors. Our job is to give him a tough night and make life difficult for him.
“But they have lots of really good quality players.”
Powell believes it will be Castleford’s sternest test yet especially as they may be missing Grant Millington, the Australian prop handed a two-game ban for “repeated punching” in Friday’s win over Hull KR.
“Hull away was a big challenge for us and we came through that,” added Powell, who has ruled out a move for former player Andre Savelio, the ex-St Helens back-row who has been made available by Brisbane Broncos. “It was a tough game, and our London performance looks like a really good one based on what they did Sunday (beating champions Wigan Warriors).
“They’re creating some waves at the moment, which is great for them.
“But this one now – Warrington away – you would say is a real significant challenge for us.
“They were in both finals last year, are a good side, well-coached while physicality-wise they’re a big team so it will be a big challenge.
“But we’re going alright ourselves. I don’t think we were at our best last week, but we managed to win the game, which is great to have in your armoury; winning games when not at your best.”
Millington was sin-binned after the fight with James Greenwood in the 71st minute of their 32-16 victory over the Robins and the match review panel handed him a Grade C repeated punching charge.
The club were last night considering whether to appeal the decision.
Powell says utility forward Alex Foster should be okay to return to action at Warrington, but he is “hopeful, not certain” that England loose forward Adam Milner will make his own comeback from injury.
Meanwhile, the only other player to face a charge from the match review panel is Hull FC front-row Mickey Paea.
He was charged with a Grade A raising his knees in the tackle on Huddersfield Giants’ Aaron Murphy during Sunday’s 28-8 win.
However, he received a zero match penalty notice so can face Leeds Rhinos on Friday despite also being cautioned for a similar offence on Kruise Leeming later in the same game.