Rodrigo Taddei is aware of the task facing Roma at Old Trafford, but insists Francesco Totti's absence will not be used an excuse.
Roma tackle Manchester United in the second leg of the UEFA Champions League quarter-final on Wednesday evening on the back of a 2-0 home defeat last week.
United are overwhelming favourites to reach the semi-finals and Taddei outlined what is required from Roma to turn the tie around.
"Those of us who have come to Manchester have to be focused and try to give not 100% but 200% in order for us to progress, something which is our aim," said Taddei.
"We are aware of how difficult our task will be. We have a negative result against us and we face a great side away from home."
The Serie A club are again without Totti after the captain failed to recover from the thigh injury which forced him to sit out the first leg.
But, while acknowledging the value of Totti to the Roma side, Taddei insists the team can achieve a big result without their talisman.
He added: "Totti is a top player and this cannot be denied.
"But we have had to play without him already this campaign and we have taken important results.
"It is understandable that others may find in Totti's absence an excuse for defeat.
"But we know that the defeat against Manchester United in the opening leg came from the fact we didn't make use of our chances to score."