كتب : Omar AbdelAziz
The highly rated midfield man scored a remarkable consolation goal in the Old Trafford hammering, but believes that the strike was meaningless amid the devastating score line.
"I scored a good goal but it was completely pointless," the Italy international told Uefa.com.
"We have been thinking about that game a lot and mostly we think of it as a 7-0 defeat. My goal has been completely forgotten.
"The final result cancelled it out and erased all the other good things we had done previously in the Champions League."
Nevertheless, De Rossi is hopeful that the Giallorossi can repeat last season's 2-1 home win over the mighty Premiership champions.
"United are very strong, as results in their domestic league and the Champions League show. But they are not unbeatable.
"They have been beaten in the league and we beat them last season at home. There are no unbeatable teams even if, unfortunately, we are facing United at the peak of their form. I am sure they have weaknesses.
"This match is a bit odd because of the 7-1 last season but our approach has to be the usual one."
Totti Absence
De Rossi is likely to wear the captain's armband instead of injured skipper Francesco Totti, whose absence could be crucial for Luciano Spalletti's team.
"It's a pity Totti will not be playing but all the players in the squad are ready to make a big contribution, even if they are not from Rome or are not Roma fans like me and Totti," he said.
"The real strength of this Roma side is the squad and the generosity of every player."
Totti has been ruled out of the game with a thigh injury, but Roma hope to have him back for the second leg.