Napoli defeated BVB 2-1 on the night.
"I am satisfied, as we did everything we talked about before the game," he told Sky Sport Italia.
"We knew Borussia were very dangerous on the break, but we talked about intensity and everyone helping out in defence.
"Last time I said the team was at 72 per cent and I still think we can improve a lot. Tonight against the European vice-champions I have to be satisfied and positive, as it's a great result.
"These new players - like Gonzalo Higuain, Jose Maria Callejon and Dries Mertens - were of international quality. It was all about giving the group confidence and players like Marek Hamsik and Lorenzo Insigne are enjoying this style of football. I am sure in one or two months it will be even better."
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