Pearson's men stunned United when they recorded a 5-3 win in a thrilling Premier League encounter at the King Power Stadium in September.
United opened up a 2-0 lead early on in that fixture, before Leicester clawed their way back to claim a memorable three points.
Leicester's season hit a downward curve after that triumph, as they went 13 matches without a win.
Recent victories against Hull City and Aston Villa - together with progression to the fifth round of the FA Cup - have helped raise spirits in the East Midlands, although Leicester suffered a 1-0 home defeat to Stoke City last time out in the league.
Pearson is confident his players will not be distracted on Saturday by fond memories of their United scalp.
"I think we've spent so long putting that behind us," he said. "It's long gone.
"We're looking at this game from the perspective of where we are now, and that's it.
"We just want to concentrate on how we prepare for this game, knowing full well that a lot has changed since then in terms of ourselves and our opponents.
"They've had a very good run of results, played different formations.
"It's always a difficult place to go, but our players are looking forward to it and we need to look forward to games like this.
"Big stadiums, big teams we're playing against and it's important we go there and do what we can."
Fourth-placed United, meanwhile, are out to avenge that unexpected defeat.
Writing in his blog earlier this week, Juan Mata said: "The previous match with them left us with a bad taste; we want to change that and offer a good game to our crowd."
United are without Ashley Young (hamstring), while Leicester could welcome back Liam Moore (ankle) and Matthew Upson (foot), but Chris Wood (ankle) has been ruled out for three weeks and Riyad Mahrez remains on Africa Cup of Nations duty with Algeria.
