Nadal is looking to win his 11th French Open and is favourite to beat Belgian Dominic Thiem.
However, Whitaker believes Thiem can come out on top in his first Grand Slam final if things go his way.
She says Thiem must take advantage of Nadal’s early match nerves and also hope the weather is not to the Spaniard’s liking.
“He (Nadal) absolutely did admit it (he gets nervous),” Whitaker said on the Tennis Podcast.
“He said ‘I’m a human man, a human person and I get nervous’.
“It’s the same old refrain with Rafael Nadal but there’s two things I keep on hearing in analysis about beating him.
“They are the first set is everything, and the weather is everything. You need to clinch that first set because he is coming out nervous.
“He is taking a while to warm up into matches and certainly the (Juan Martin) Del Potro match would be further evidence.
“I think he would still be out there waiting for the result had he won that first set, wondering what would happen.
“The weather, I watched a bit of footage of the (Robin) Soderling victory over Nadal here in 2009.
“It was even heavier and more overcast than I even remember it being.
“It’s no accident and the tale of the tape from the (Diego) Schwartzman match was the weather couldn’t have been more different.”