"As far as Cardiff next weekend is concerned, we need the fans there," said the Wales striker.
"When you are playing in front of 12,000 in a stadium that holds 70,000 it is not easy to motivate yourself.
"We could do with a few more fans there, but we need to lift them and give them something to shout about.
"We need three points, that would help, and if we don't get them it would virtually close the door to qualification."