Cottagers' fans elected to stay away for the Uefa Cup clash with Hadjuk Split two weeks ago and the empty seats have upset the Fulham players.
"One or two of the players do get a bit upset with the crowd situation," said Knight.
"They're trying to do it for the fans - so it's disappointing when the fans don't turn up.
"It's very frustrating to go out there and play in front of a half-empty ground.
"The fans want us to get a new stadium - but they're not helping us by not turning up to games."
The West Londoners will share QPR's Loftus Road ground for two seasons as they face a backlash from local residents over the redevelopment of Craven Cottage.
