He feels their rivals no longer view them with the same trepidation as they did when they lifted the trophy in 2008 and reached two of the next three finals.
"This could lift everyone," said the France defender. "If we can beat Madrid then the response it gives to other teams would be important.
"Don't forget, last year we were knocked out in the first stage of the Champions League and maybe people have that image of Manchester United in Europe.
"We have to change that. That is why I think this is the perfect year to show who we really are.
"We can't miss this opportunity to show ourselves, it would be a massive disappointment.
"This is why I'm really looking forward to the match with Real Madrid. I've been waiting for a big European tie like this for a long time and it's probably the biggest European game since Barcelona in 2008.