The American goalkeeper has been in superb form this season and was Man of the Match in the narrow defeat to Manchester United on Saturday.
The consistency of Kasey is a huge boost to the team, the defensive side of which has had great alterations forced on it each game due to injuries.
"The defence was changed and I think it's been like that for most games," reasoned Dean. "We got to be quite pleased, Kasey is one fire and has been playing great all season. That gives us a lot of confidence in front of him.
"With the form he's in you know if they get past you they've still got to beat him and at the moment he is brilliant.
"He was having one of those games on Saturday where he was making great saves, great reactions and it was going to take something like a penalty to beat him."
Dean feels that the team gave a good account of themselves at Old Trafford and says they entered the game in a confident frame of mind.
"We were well up for Saturday and we stuck to our game plan. If my chance had gone in we might just have come away with three points.
"The way we've started the season we've got to be confident. We took a bit of confidence into the game on Saturday and felt there was no reason why we shouldn't go there and get a result.
"We were unlucky in the end but, with the way we're playing, from our next two games against Middlesbrough and Blackburn we must be looking to take four to six points."
Dean Richards says the form of Kasey Keller has instilled an added confidence in the players in front of him.