Castleford host Warrington Wolves in their final regular round fixture knowing they must win to book a place in the top six.
It will be Powell’s last game of his eight-year reign if they do lose given he is joining Warrington Wolves at the end of the season and it is definitely his final match in charge of Cas' at Wheldon Road.
Tigers played at Wembley in July when they lost out in the Challenge Cup final to St Helens and Powell admits this week has a similar sense of occasion.
“There is an intense feel about the players,” he said, with captain Michael Shenton and Australian prop Grant Millington also knowing this will be the final game of their careers if Tigers do not secure a spot in the play-offs.
“There’s a different feel when it comes to knock-out rugby and it does feel like that.
“This is it for us. This is it. Every game we play from here on we have to win and that gets something else out of you.
“Obviously, Warrington haven’t got that. They have other motivations. For us, it does feel like this is it.
“The players have trained in that way today.”
Warrington, already secure of third place and a home play-off eliminator next week, are missing both their hookers - the England international and former Castleford No9 Daryl Clark as well as Danny Walker.
Powell hopes his own England hooker McShane will feature after missing Friday’s 26-19 loss at Hull KR due to an ankle injury while half-back O’Brien should also be back.
“We’ll check him (McShane) in the morning,” he said.
“He’s run today. I'm hoping he will be okay.
“He’s a class player isn't he and clearly our number nine is someone so pivotal to the team.
“Obviously, looking at the Warrington squad, they have a couple of nines missing so they’ll understand how difficult it was for us last week.
“It’s just a good opportunity for us. We had to win last week or this week to be in the top six and it comes down to this.
“It’s a great opportunity for us to put it all on the line and play well.
“Gaz (O’Brien) should be okay. He’s trained today and we’ve got Wattsy back from suspension.
“We have a few decisions to make around our middle unit. But I’m leaving people out at the moment and we haven’t always had that.”
Unfortunately, Oli Holmes, the long-serving Castleford second-row who follows Powell to Warrington in 2022, is out after suffering a season-ending neck injury at Hull KR.
On the 29-year-old, Powell said: “I’m so disappointed for him. “He’s been one of, if not, our best players this season.
“We just did a defensive highlights video this morning and he’s on pretty much everything. He’s such a tough player.
“Both sides of his game have improved this year so it’s a huge disappointment for him personally and I feel for him as everything he's done from a rugby league perspective has been at this club and he’s put his heart and soul into all of it.
“I’m hugely disappointed he can’t play his last home game here but we all do this together and guys who aren’t playing it means just as much to those as the guys who are playing.
“The stories are all around us. This has got to feel like a must-win game for us and it does. I hope the performance justifies that.”