The Australian has been plagued by questions about his attitude throughout his career, but things seemingly came to a head when he appeared to give up last week in Shanghai, an incident that saw him fined and given an eight-week ban.
Kyrgios was reportedly “distraught” with his actions and Cash has now called for Tennis Australia to help him battle his demons.
The 1987 Wimbledon champion admits he fears for the 21-year-old's future in the game and is worried that without the right guidance, both on and off the court, he may decide to end his career.
"I wouldn't be surprised (if he quits) but hopefully that's not the case," Cash said. "Anybody's got the opportunity to walk away but if it's not good for his health then I think he should do that.
"But with some good things in place for his health and well-being, and a revised schedule... he can go out there and enjoy his tennis, which is what we want to see."