Schalke have not given up hope of reaching the Champions League finals despite facing the task of attempting to overturn a 2-0 aggregate deficit.
Farfan said: “Miracles appear in the world of football and we need one on Wednesday at Old Trafford.
“Schalke are not going to England for the tourism, but to take our last chance.
“The match will be different when compared to the one in Gelsenkirchen. We need goals and this is our objective in Manchester.”
He added: “In the first match, United were better. But now the situation could change.
“We play without the big pressure because people consider that the English are in the final.”
