At the Go Big press conference before UFC 191 in early September, Jedrzejczyk and Letourneau went nose to nose and the UFC women's strawweight champion was impressed.
"After that, I was like, 'F*ck, this chick is tough,'" Jedrzejczyk said Wednesday at UFC 193 open workouts.
But the Polish titleholder sensed a crack in the armor a few weeks later when the two co-headliners were in Melbourne, Australia for a UFC 193 press conference.
"At that moment I could see it in her eyes," Jedrzejczyk said. "Her hands were sweating. She's afraid already -- believe me. But it's going to be a real war."
Jedrzejczyk (10-0) will have her second title defense Saturday night when she takes on Letourneau. She has risen quickly this year, winning the belt from Carla Esparza via TKO at UFC 185 in March and defending it three months with another finish against Jessica Penne.
In both of those fights, Jedrzejczyk got into her opponents' head -- or at least attempted to -- during fight week. Joanna Champion is certainly not shy when it comes to pre-fight talk to the media or even to her foes directly.
A reporter asked Wednesday about Letourneau's teammate Hector Lombard boasting that Letourneau would dominate on the ground against the multiple-time former Muay Thai champion. Jedrzejczyk met the inquiry with a broad smile.
"Try," she said. "Try to do it, c'mon. If you want to play on the ground, just let me know. We can go to the ground from the first seconds of the fight. We can just play there."
Jedrzejczyk, 28, has excelled standing up in all of her UFC victories. Her skills on the ground are mostly unproven, though she has shown exceptional takedown defense.
"It's MMA," Jedrzejczyk said. "I'm a complete MMA fighter. I expect everything. I'm ready for all of it.
"I like to fight on the ground. I'm learning every day. I think I'm good. Maybe I didn't show it in the fight."
Jedrzejczyk is wildly confident, which should not be a surprise since she's more than a 20-to-1 favorite against Letourneau. However, she was extremely confident going into the fight with Esparza, too, and she was the underdog then. She doesn't think being sure of herself will be any kind of disadvantage.
Letourneau, Jedrzejczyk said, is not going to sneak up on her. She has respect for her.
"You know why I'm so confident?" Jedrzejczyk said. "Because I am working so hard every day. That's why I am different than the other fighters and my opponents and the challengers. That's why."