Manchester United boss Ralf Rangnick says failing in the Champions League is not worth considering.

United host Atletico Madrid in the second-leg of the round 16 tie tomorrow night.

Asked if it would be a blow if Atletico were to win, Rangnick replied: "I would change the question round and ask how much of a boost if we win the game tomorrow.

"We have a fantastic opportunity to be one of the best eight in Europe.

"The game against Tottenham showed the level we can play at. With another 20% on top of the game against Tottenham, I am sure we can win tomorrow.

"It is more about our own ambitions. We want to proceed and show we can compete with the best teams in Europe. We will try everything to win the game tomorrow.

"It's very important (not to concede first). Even more so against a side like Atletico who don't mind the opposition having the ball. If possible we have to make sure we don't concede at all. But it will definitely be important to score the first goal ourselves."

Rangnick also spoke of their top four hopes.

"It doesn't matter how we qualify for the Champions League next season, it is about what is realistic," said Rangnick. "Tomorrow is the Champions League and we'll try everything we possibly can to win the game tomorrow to be in the last eight. Even if we did that there are still a number of good teams in the competition.

"Right now, Arsenal is in good shape so it is clear we need to win all games in in the Premier League. Tomorrow is the Champions League. We cannot wait for the kick-off tomorrow. We are highly motivated."