Mauricio Pochettino has warned his Tottenham Hotspur stars that they must make a fast start to their Champions League campaign or risk another early exit.

Pochettino's side failed to make it past the group stage of Europe's elite club competition last season.

Tottenham's downfall was triggered by poor results in their home games at Wembley, where they were beaten by Monaco and Bayer Leverkusen.

The north London club are back at Wembley this season while White Hart Lane is being redeveloped and they kick off their Champions League group fixtures against Borussia Dortmund at the national stadium on Wednesday.

Keen to avoid another disappointing European adventure, Tottenham manager Pochettino has underlined to his players that getting off to a winning start is vital, especially with holders Real Madrid also in Group H.

"Last season, after the first game at home against Monaco, it was difficult to change the dynamic. I think it's so important to try to win the first game and get three points," Pochettino said.

"It will be tough because Dortmund is a great, great team but in our mind our mentality is to try to win and be aggressive from the first ball.

"I think tomorrow is such an important game. To start well in the competition and get three points will be key to the future of course.

"It's true that in theory Real Madrid are first, then Dortmund, Tottenham and APOEL compete to be second. That's the theory but football is not theory."

Tottenham have struggled at Wembley in recent years even when they aren't playing European games.

Losers in eight of their last 12 matches at the hallowed venue, Spurs have been beaten by Chelsea and drawn with Burnley in their two games there this season.

Pochettino hopes Tottenham's players can block out all talk of a Wembley curse and show they have learnt from last year's harsh Champions League lessons.

"It's a tough competition with the amount of focus and energy you need, it's massive, maybe the same or more than the Premier League," he said.

"Last season was our first experience of the Champions League. Previously we played in the Europa League, for 98 or 99 percent of the players, and for myself too.

"We know very well what the competition demands from you, and I think it is so important, that experience from last season. 

"It was a very painful experience because we could not be at the level we should have been, but today it's not an excuse. 

"We need to be ready to compete at a higher level."

- Big stage -

Pochettino hinted he could hand a debut to right-back Serge Aurier, a recent signing from Paris Saint-Germain, but Dele Alli is suspended after a red card in the Europa League last season.

Tottenham striker Harry Kane expects his team to hold their own against the Germans, even without star midfielder Alli.

"He's a fantastic player and we will miss him. But fortunately we have a fantastic squad and I'm sure whoever comes in will be ready to compete on the big stage," Kane said.

"Last year we got off to a bad start. We've got to make sure we win our home games because going away in the Champions League is always going to be difficult, no matter who you play."

Dortmund beat Tottenham twice in the Europa League in 2015-16, but they travel to London hampered by injuries to several stars.

Beaten at Wembley by Bayern Munich in the 2013 Champions League final, Dortmund hope to make it another miserable night for Tottenham in their adopted home.

"It's going to be a huge challenge, but I see ourselves as being on the same level as Tottenham," said Dortmund sporting director Michael Zorc.