The Magpies dropped off top-spot last week for the first time since August and the Harriers missed a chance to replace them when they dropped points against Nuneaton Borough.
They've won just once in their last five outings, dropping ten points from a possible 15.
And for MacFarlane, Saturday's huge clash is a perfect opportunity for his side to put the past few weeks behind them.
"It's a massive game," he told the club's YouTube service. "It's one we're looking forward to for sure.
"Hopefully we can make amends for the past couple of weeks because I'm pretty positive that the group can move on from this.
"It's a long season and I'm confident that come the end of it that we'll be up there."