Rudi Voller admits he underestimated the situation at AS Roma during his difficult few weeks in charge.
The German coach said: "If I am honest, speaking from the heart I think I underrated some things. The team was, physically, not at the right level and we did not have time to fix that.
"Then when I saw what happened against Bologna, I thought the best decision would be to leave."
He added: "What I said that morning after the game will never be made public. I made the decision so to open the eyes of some people at the club.
"I still feel I have many friends there. Cassano? I am sure I will enjoy watching him play when he comes to Germany in 2006 for the World Cup."