Cassano joined Inter last week after telling the Diavolo, a club he only joined in January 2011, that he wanted out.
"He asked to be sold with insistence," Braida stated. "He asked us once, five times, 10, 100 It got to the stage when there was nothing else we could do.
"Obviously something wasn't right. I had a meeting with him, but I didn't understand the motive for his departure. He didn't tell me.
"It's all a bit complicated," Braida added. "There are problems in life that can be resolved and others that can't, but he should have been clearer."