The Spaniard insists the Red Devils will look to win at the Etihad Stadium on Monday, despite knowing a draw will keep them in the driving seat for the title run-in
United enjoys a three-point lead over City at the top of the Premier League with just three matches to play, but knows a repeat of October’s 6-1 Old Trafford humiliation at the Etihad Stadium will see the advantage wiped out.
A draw would be enough to keep Sir Alex Ferguson’s men in control, but De Gea insists the idea of playing for a share of the spoils is not even in their minds.
“We won't park the bus or try to get a point,” he told Goal.com. “We don't know how to do it and that would mean giving them the advantage on the match.
“We are approaching this derby as a final because it really is, but we have more chances than them. They need the victory and that's an extra pressure they could resent on the pitch.
“I don't expect a crazy match but rather a tactical one. This is not a knockout tie but a match in which a goal can give you the title, so we have to remain calm.
“This is the match of the season and we are planning up to the most minimal detail. We cannot fail.”
United faces a City side which has scored 12 goals in its last three matches but, while he admits it will not be easy, De Gea is confident the Red Devils will rise to the occasion.
“Man City are very dangerous, especially attacking,” he added.
“Silva and Tevez have clicked and that makes them create many dangerous chances. We have to stop those two if we won't want to suffer on Monday.
“The ambiance will be electric and the fans will be against us but I won't be affected.
“I have played at the Bernabeu, Camp Nou, Turkey, Greece and Italy. I actually play better in these situations.
“My teammates have been very motivated during this week's training sessions. We know what we are fighting for and we know that we will play a final tonight.
“We won't think about losing but it would obviously be very hard if we finish the season without winning a title and after having the Premier League title in the tips of our hands.”
A record 20th Premier League title would be a remarkable achievement considering United’s shaky form during the first half of the season.
But since the turn of the year the Red Devils have been relentless in their pursuit of City, with De Gea gradually growing into the No.1 shirt and playing a key role.
Everton’s stunning late comeback at Old Trafford last Sunday has given Roberto Mancini’s men renewed hope, but De Gea insists United has not grown complacent at the top.
“I think I have improved a lot since I arrived to England,” he continued. “My beginnings weren't very good or very easy but I feel a lot better now. Even the coach says so.
“This season has had lots of comings and goings.
“City seemed to have their work done but we were able to overcome them and now it seems to be balanced. I always prefer to be leading than to be trailing.
“These last points we have relinquished are not because of overconfidence. There are no easy rivals in the Premier League and we have suffered in the last few weeks.
“I hope we won't regret it at the end of the season.”