McFarlane, who returned for a second spell as interim coach last month after Chelsea sacked Liam Rosenior following a five-match losing run, began with a 1-0 win over Leeds United that secured a place in the FA Cup final.
Chelsea, eighth in the Premier League on 48 points, host Nottingham Forest on Monday, and McFarlane struck a realistic tone when pressed about Champions League qualification being out of reach.
"I think you're right when you say that. We have to win our games and not think about anything else," he told reporters on Friday.
"We need the fans to bring a positive energy and get behind the team. There's a lot to play for."
Chelsea will face Manchester City in the FA Cup final on May 16th, and McFarlane said last week’s victory had lifted spirits at Stamford Bridge.
"It's always difficult when you're not performing and not getting the results," he said.
"It's amazing how a win can change the feel and atmosphere of the group."
On the injury front, McFarlane said captain Reece James, who is recovering from a hamstring strain, and defender Levi Colwill had returned to training.
"A little way to the game, so we'll see how they do, but both are looking promising," he said.
"Levi has had a long injury, Reece had a really good run and was then injured again, so we don't want to push too much."