In his interview with the TV doctor, the performer made it clear that he wasn't drunk and merely slipped on a stage monitor, explaining:
"I certainly wasn't intoxicated, and it has nothing to do with why I'm leaving [the industry]. Certainly, my dementia has contributed to the reason why I don't want to go out, and I don't want to hear, 'Well, he looked like he was drunk.' … I wasn't."
Cassidy is set to perform two final concerts before ending his touring career at the B.B. King Blues Club & Grill in New York City on March 4.
Watch the sneak peeks of Cassidy's heartbreaking chat with Dr. Phil (below) — and catch the full interview on Wednesday.