The Whites and Clarets are level on points but United's far inferior goal difference means that Marsch's side would be relegated if failing to out-point Burnley on the final day.
The Clarets are at home to Newcastle United as Leeds head for Brentford as part of the full programme of 4pm kick-offs and Marsch has issued a strong vow to the club's fan base ahead of the season finale.
Asked if he had a message for United's fans travelling down to London, including those going down with no ticket, Marsch said: "I would say in general that I've had such a positive experience with the fans and that when we've been in the stadium, the support for the team and the extra push that they've given us has always been magical, truly magical.
"I know that there's a lot of emotion that is always added to big moments like this.
"I hope that they find a way, no matter what, to be at our side and to know that we're going to figure this out.
"We're going to get this right, we're going to get it right on Sunday, and we're going to get it right in the future and whatever way we're going to move forward."
Paying tribute to the support has has received since coming into the job, Marsch said of United's fans: "I haven't had one negative experience.
"I've had only positive experiences in the community and positive support.
"I don't think people always recognise me, sometimes they recognise me, sometimes they don't.
"I know that there are fervent fans that their emotions can sometimes get the best of them in some negative ways.
"But I've seen only the positive effect of our fans and I've tried to reiterate that that's massively important for our players to feel and know.
"There was one match where I read a letter from a fan before the match and said to them (the players) that it's special to be a player for Leeds United, that it's unique in many ways but to know that the vast majority of the people are represented by what that letter was, which is how hard they were supporting them, how hard they were behind them, and that they are their heroes.
"This letter said that and I wanted to make sure that our players understood that."