Confirmed: The core facts are supported by the cited primary sources.
Explore the PANCRASE archive →The confirmed cancellation
PANCRASE updated its official PANCRASE 365 page on August 27 to mark Kazuki Kasai vs. Sharman Debzhiev cancelled. The promotion says Debzhiev was injured in training; it has not announced a replacement opponent for Kasai.
What remains on the card
The September 6 event remains scheduled for Tachikawa Stage Garden. PANCRASE still lists the middleweight championship between titleholder Koshiim Sardorov and challenger Genpei Hayashi as a five-round bout, along with a flyweight next-challenger contest between Sarutobi and Genta Shindo.
Fight Atlas will not list Kasai–Debzhiev as an upcoming fight or attach a result or record change to either fighter. Any replacement booking will require a new direct promotion confirmation.