They defeated Salford 28-18 at the AJ Bell Stadium last Friday to quickly respond after their first defeat of the season against Wigan Warriors.
The sides meet again at Emerald Headingley to get within just 80 minutes of Wembley, and Castleford are firm favourites.
But, on his club’s Challenge Cup prospects, Powell insisted: “It’s tough to get there and tough to win. Salford will be highly motivated and ready to come and win the game and be in a semi-final themselves.
“We aren’t taking anything for granted; winning the game last week doesn’t make any difference at all.
“We’ve got to come up with a performance that is good enough to get us into the semi.
“We can’t look past what’s right in front of us at the moment.
“As a team, Salford have got Dan Sarginson and potentially Pauli Pauli coming back in.
“They have got a big and dangerous squad and we certainly won’t be underestimating them.”
Nevertheless, Powell hopes to go one step further than seven years ago when – in his first full season in charge at Wheldon Road – he led Tigers to Wembley but came unstuck 23-10 against Leeds Rhinos. Castleford have only won the Challenge Cup four times in their history, the last success coming in 1986, and it would be some way to bow out for the coach who moves to Warrington Wolves at the end of this campaign.
Asked if he would have done anything any differently in 2014, Powell said: “Leeds were pretty smart how they played against us. (But) we didn’t get our preparation right, to be honest.
“We stayed in a hotel right on Wembley and it was the wrong place.
“I didn’t have too much to do with that, so I’d definitely change that.
“I just thought Leeds played awesome.
“We had a lot of players playing in their first final and we didn’t really play as well as we’d have wanted to.
“But this is a different team with a different mindset, different qualities in there.
“We just want to get there and show what we can do, play to our potential – that’s the main thing when you get into a final.
“But first and foremost we’ve got to get through this game and that’s all we are looking at.”
Captain Michael Shenton, second-row Oli Holmes – who scored at Wembley – and prop Nathan Massey are the only survivors from the Castleford team in 2014 now looking to return.
They should all feature tomorrow and, though Powell has lost Cheyse Blair and Greg Eden to injury, he could have Gareth O’Brien, George Griffin, Jordan Turner and Daniel Smith back to bolster his squad.
They have all been named in the 21-man squad along with James Clare, the winger who is included for the first time this campaign following injury.
“There’ll definitely be a different look and freshness about it [the team],” he said.
Salford also welcome back Elijah Taylor, Ryan Lannon and Dec Patton from injury.
However, they have lost Andy Ackers (ankle) and Josh Johnson from last week’s 17 while Krisnan Inu and Morgan Escare drop out of their 21.
Support The Yorkshire Post and become a subscriber today. Your subscription will help us to continue to bring quality news to the people of Yorkshire. In return, you’ll see fewer ads on site, get free access to our app and receive exclusive members-only offers. Click HERE to subscribe.