Hugo Lloris is hoping that Tottenham can raise their game for the UEFA Champions League.
While Spurs have continued their impressive winning form in the league, they will face a big test against the Bundesliga table toppers.
And Lloris knows that only if they are at their best do they stand a chance against Dortmund.
"Dortmund play fantastic football with fantastic players and I'm not surprised they're top of the league in Germany," said Lloris to reporters.
"It's going to be very, very difficult. We need to improve the team performance compared to yesterday and we need the stadium to help us. Some days it's difficult to deal with Wembley but, hopefully, in this big game we'll receive this help from the crowd.
"Leicester played fantastic and we won the game thanks to our spirit and character. Without that, we could not win. [But] we need to improve the team performance.
"Against a bigger side we couldn't have won that type of game. It's up to us. But the most important thing was to get another three points in a difficult period. We kept consistency, so it's a great feeling in the changing room.
"Leicester had 20 shots and against a bigger side it would be difficult to win that way. But sometimes you deserve to win, like the game against Man United, and you lose. Yesterday, Leicester deserved better but we won. This is the League. The mentality is great in the changing room and we showed that again on a difficult day.
"In terms of performance, we have to do better if we want to dream of big achievements. But in terms of mentality, spirit, you cannot ask more. Now we need to deal with a few more games and then, hopefully, the squad will be full again until the end [of the season]. First of all we need to keep our place in the top four and then maybe more. We'll see."