The Blues have displayed some impressive form of late, winning three of their last four games, and the assistant boss feels that the White Hart Lane crowd can help the team achieve the victory that could provide the spark for a push up the table in the final stages of the season.
"We need the fans to be up for the game," urged John. "As I've said before, I know it has not gone right for us in the last few games, but support for the team is vital.
"It is very important, especially when you play teams like Birmingham at home, you need the fans to be more vocal, more supportive to the team and I'm sure they will be. It is a very important game for the club."
John went on to agree that, while the management will never waver from their commitment to good attacking football, a win is what matters most on Saturday after the recent setbacks.
"We need to win because we've lost three on the trot. It would be nice to win playing great football, but we need to win. Three points is vital.
"Me, and obviously Glenn as well, like to play good attacking football for the fans, but we need to be positive and concentrate on winning the game - getting the three points. Confidence will breed from there."
John Gorman has called on the fans to be as vocal as possible in support of the team against Birmingham on Saturday to help get the season back on track.