They head to Huddersfield Giants having lost for the first time in four games against Wigan Warriors last week.
It was a painful defeat for more reasons that one – Castleford felt harshly treated by referee Ben Thaler in a controversial 33-26 reverse – and it has now diluted their chances of making the top four.
But Powell admitted: “You have performances and results that, for whatever reason, go against you.
“It’s important that you get straight back. We’ve probably learnt some lessons from that Wigan match which is key.
“Now we need to get back up. We need to win this; it’s a key game for both teams so there’ll be some desperation there.
“We need to play well and I think we have, if I’m honest, over the last month so we need to rock up again and hopefully get the two points but we know it will be tough.”
Huddersfield have won three of their last five games after spending the early part of the campaign in bottom place.
They, too, however, suffered a setback when letting a 16-0 lead slip to lose 24-20 at Widnes on Sunday, the Vikings finally ending their eight-match league losing sequence.
Powell conceded: “Huddersfield have been in and out of form.
“They had a real good win at Magic against Saints when they looked very sharp and did some good things but will then be disappointed at coughing up a comfortable margin being in front last week to lose like that.
“Widnes beat a lot of teams on their own patch so there’s no shame there but we have to do what we can do.
“We have been pretty good with the ball in the last few weeks. We dropped off a bit defensively against Wigan but have got to be on it now.”
On-loan Larne Patrick is unavailable against his parent club but loose-forward Nathan Massey returns and Joel Monaghan is available after missing last week due to illness.
Meanwhile, on Thaler, Powell added: “I spoke to Steve Ganson (head of match officials) and we’ll see what his response is.
“They’ve reviewed their performances. I had a good chat with him (Ganson) earlier and we had some common ground there so we’ll see where that goes.”