In a chat with reporters, Norman said that his charge remains unpredictable from week-to-week.
"He's a very interesting player to watch, because you never know what to expect," Norman said.
"This week we saw the greatness of Stan, but next week it could be something else."
On the way to winning in Paris, Wawrinka showed great form beating world No.2 Roger Federer in the quarter-finals and then world No.1 Novak Djokovic in the final.
Norman confirms that Wawrinka worked hard in training and felt that he could be a contender if he got past the first couple of rounds in Paris.
"Every day he has been putting in the work and every day I have been really happy when I have gone to bed," said Norman.
"But, going into the tournament, I felt that if he could get through the first couple of rounds he was going to be dangerous and a contender.
"But I never believed it until maybe the first match point. It was, like, ‘Now he has a chance to win it'," he added.