Fulham had fans inside the ground on Sunday afternoon for the visit of Liverpool and grabbed a 1-1 draw against the Premier League champions.
Scott Parker’s men moved on to eight points from 12 games, seven better off than bottom team Sheffield United, and McMahon thinks the fans had an impact on the match with the Reds.
“Not if you’re Sheffield United [fans aren’t coming back]”, McMahon said post match on LFC TV.
“Imagine being a Sheffield United player or the manager when you look at Fulham today.
“You could argue they [the fans] made a difference, made a big difference.
“Now if Sheffield United have got that, 2,000, 2,500, wouldn’t that make a difference for them, especially at this moment in time, the confidence booster it would give them”, he added.
Sheffield United are already in trouble and have lost eleven of their 12 league games so far.
They play host to Manchester United on Thursday night, but will again be operating in front of empty stands, as Chris Wilder looks to try and inspire his players to all three points.