De Rossi dubbed the Champions League result as "shocking".
"The result is shocking. We must take the positives and learn the lesson from this night, perhaps helping us realise our real dimension," the midfielder told Sky Sport Italia.
"We and the city had been waiting for this match for a long time and it's a shame we got this result. Seeing the fans applaud us at the end of the game felt like a stab in the heart. The season is long and potentially rich in satisfactions, so we will pay them back for their support."
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