Samantha Stosur knows she must be brave or perish when she takes on Spanish powerhouse and reigning Wimbledon champion Garbine Muguruza for a place in the French Open fourth round on Saturday night.
For so long one of the premier athletes in women's tennis, Australia's veteran clay-court exponent says tennis's new generation of fearless stars have taken the game to unseen physical levels - and only the bold will survive.
At 24, Muguruza is 10 years Stosur's junior and epitomises the supreme specimen the former US Open champion is talking about.
The only player to have upstaged both Serena and Venus Williams in grand slam finals, Muguruza hit Stosur off the court in the 2016 French Open semi-finals en route to landing her maiden major in Paris.
Stosur fears a repeat could be on the cards if she doesn't take it to the world No.3.
"Ninety five per cent of players play big, aggressive games," Stosur said of the new-age power game.
"They hit the ball harder, it's deeper. In general, everyone's a better athlete now and you've got to be ready to step up and hit it.
"If you just try and push the ball around, unless you're an unbelievable mover, or really great at defending a bit more, like a (Agnieszka) Radwanska - she might be the exception in terms of being at the top of the sport without possessing a big power game, life's really tough.
"You've got to have a big shot. It's kind of been proven with grand slam winners in recent times.
"Every winner's got a really good shot that they can try and rely on, a big weapon.
"The level now, players ranked in the top 50, top 100 now, are probably better players than they've ever been in those rankings brackets."
It was Muguruza's deadly depth and weight of shot that overwhelmed Stosur in Paris two years ago.
But the Australian has beaten Muguruza on clay before, in 2014 in Madrid, and pushed the Spaniard all the way in a 7-5 6-7 (2-7) 7-5 loss in their most recent encounter, in Brisbane last year on a hard court.
Back in the last 32 at Roland Garros for the 11th time, Stosur has nominated serving as the key as the four-time semi-finalist and 2010 runner-up attempts to enhance her envious record in the French capital.
The winner will advance to a meeting with either Slovakian Magdalena Rybarikova or Ukraine's Lesia Tsurenko on Monday for a spot in the quarter-finals.