Magnus Norman, who has been working with Swiss star Wawrinka for four years, believes he can become world No. 1 if he produces his best tennis on a regular basis.
The 31-year-old Wawrinka did just that in his grueling four-set win
over world No. 1 Djokovic in the Flushing Meadows final last month -- his third grand slam title since teaming up with the Swede.
But earlier in the tournament he had found himself match point down to unheralded Briton Dan Evans before squeezing through in five sets.
And it bothers Norman that Wawrinka can sometimes find himself in big trouble against -- or losing to -- "some opponents that you don't see Andy (Murray) doing or you don't see Novak doing."
"The thing that we're working on is to make him a bit more consistent, because Stan is very much up and down," the 40-year-old admits.
"Now he's No. 3 in the world -- but if you want to reach even higher you need to produce good tennis on a weekly basis.
"Andy and Novak are much more consistent than Stan, so that's the main thing we're working on."
Wawrinka credits his mental strength
for steering him through some tough moments on his way to glory in New York.
And Norman, who as a player reached No. 2 in the rankings, says although he felt "something big" was going to happen soon, he didn't expect that to come at Flushing Meadows.
"The results were not there in the last few months, but I knew that he was working hard," he explains.
"So I was feeling that -- maybe not in the US Open -- he was going to play good and something big was about to happen again."
Now it has happened, the sky is the limit for Wawrinka -- because Norman believes the Swiss has the talent to propel himself right to the top of the rankings.
"The level is there -- it's not like he doesn't have the level," he says. "I don't see why not. It is about the consistency.
"He needs to be connected mentally and physically, week in and week out, and it's the challenge for me as a coach to bring that out.
"Physically he is very strong and he doesn't get stressed if he loses the first set, and that happened many times in New York. He still feels he has the time to get back into it."
But despite the high stakes and the higher pressure of life as a top player, Wawrinka still knows how to unwind.
"He's like a normal guy," Norman says. "He's like the neighbor that you want to go out for a beer with. He can have a good laugh -- he's got a great personality.
"We have got to know each other very well in the last four years. It's a strong relationship. We have fun off the court and we work well together."
And Norman is quick to stress that Wawrinka's success is not just down to his influence, emphasizing that "all the hours of hard work he put in before we started working together are starting to pay off."
"When I came in we started to work a little bit on getting him to believe a bit more in himself, especially on big occasions," adds Norman, who previously worked with two-time French Open finalist Robin Soderling, while Grigor Dimitrov was one of his Good To Great
"Maybe he has changed a few things in his game, like how he plays the important points. But it's more about the confidence and the fact that he has worked hard for so many years."