But the colourful Kasatkina is in the mood to "battle for every ball" to pull off her third career victory over a top-ranked player, sounding as if she's enjoying taking her opponents to testing places in what she likens to the 'tennis jungle'.
Sabalenka, a big Jannik Sinner fan, reckons it was "really painful to see" the men's No.1 capitulate in the brutal heat to Juan Manuel Cerundolo on Thursday. "I felt so bad for him," she sighed.
But with Saturday's third-round encounter against her old friendly foe Kasatkina set to be played once more in 30C-plus temperatures on Court Suzanne Lenglen -- supposedly the last day of the heatwave -- she's confident she'll handle the conditions again to continue her dominance of the Russian-born Melburnian.
"She's amazing. It's always challenging playing her. I never look into the previous matches going into the match against her, because it always can be tricky, she's a fighter," said Sabalenka of Kasatkina, brushing aside the 7-2 advantage she holds.
"She's putting all of the balls back, you have to really work for each point, especially on the clay court. So it's another tough match, but I'm ready to fight, to face every condition possible. I'm just super excited to face her and ready to bring the fight."
The feeling's mutual. After a troubled spell, there have been signs of the old Kasatkina reappearing over the last three weeks, winning a small WTA 125 event in Spain and a couple of wins at Roland Garros where she's clearly loved being in the thick of the fight.
"It's where it's getting into the jungle, and where you have to swim in the shit, like, for real," as she enthused in her own inimitable way after her win over Swiss qualifier Susan Bandecchi in the previous round.
Naturally, the world No.53 will start as a huge underdog after not having been able to pick up a set off the Belarusian in their last four meetings and also having lost to her at Roland Garros in 2020 when she got whitewashed in the second set.
But Kasatkina sees the conditions as a bit of a leveller against the four-time grand slam champ, who's also fallen short in four other finals.
"It's a challenge for everyone," she shrugged. "She's a multiple grand slam champion, No.1 for a reason. It's still going to be hot the day we play, so that might be to my advantage.
"I only know that she gonna go out there and hit very hard, and she will be hungry for the win.
"At the end of the day, it's going to be about how I'm gonna just fight for every ball -- and let's see."
But for Kasatkina, who's had such a trying 12 months with loss of form and confidence, even walking away from the sport for a while at the end of last season, just being part of such a big occasion gives her joy again.
"I've been through hard times, and this is what we were working for. It's going to be huge challenge, we're gonna have a beautiful court to play on, and I'm really looking forward to it."
