The Tykes are currently in the relegation zone, but a win away at Huddersfield will guarantee their survival.
A draw could be good enough, depending on Peterborough's result away at play-off chasing Crystal Palace, but Flitcroft wants his side to take control of their own destiny and not have to worry about proceedings elsewhere.
"I'm delighted we're in this position and delighted that the lads have given themselves a shot to stay in this division," he told the club's official website.
"We can only affect what we can do. We only control this game.
"This group wants to focus on themselves and it's important we do that.
"It's a game where we'll focus what we're about. It's something we're working quite hard at on Oakwell this week to put in place.
"It's going to be a massive day, whatever happens."