Chiaki's goal when she joined LAW was to improve herself and grow stronger, so that's what she chose to do between this fight and her last. While her knee, along with the rest of her body was recovering, Chiaki researched how to reverse and escape a figure four along with many other common submissions and immediately began practicing them once her body was good to go. Going into this match, Chiaki had promised herself that she would not submit in this match, no matter how much it hurt. She might lose today, she may submit in future matches down the road. But she would not lose this match by submission no matter what. That's how she would be a stronger person than the day before.
As for her opponent, Yusei Okubyo would be nothing like Chihiro. Yusei was a fair bit larger than Chiaki, had a win already under her belt, and a reputation for sadism. It was a test that Chiaki wasn't confident she could overcome. Yusei almost assuredly had the advantage in physical ability, so Chiaki would be dependent on her tactical, measured, and deceptive style to create openings against her wild and erratic foe.
All this was running through the Gamer Girl's head as she stood in gorilla position, waiting for her cue. Then when it came, "Time to get out and do this." were Chiaki's words as steely determination covered her face.