The Bluebirds are sixth in the Championship with 10 games to play, although if they were to win all their three games in hand they could even be in the mix for an automatic promotion place.
Dave Jones' side now face four home games on the spin, starting against Watford on Wednesday night, and Whittingham is fully aware of the importance of the club's fans during the closing stages of the campaign.
"I think Ninian Park could be crucial to our promotion push, the fans here are always right behind us and their support has really been paying off for us of late," the midfielder told the club's matchday programme.
"As long as we perform on the pitch and do what the fans expect of us then we know it'll get them going - that level of support is a massive help to us."
He added: "It's difficult to know what to expect (from Watford) really, it'll be interesting to see how they approach the game. One thing is for sure and that is we're confident and fully focused on the task in hand."