Tottenham captain Hugo Lloris admits they lacked fight for their Carabao Cup semifinal first-leg defeat at Chelsea.
Spurs will need to overturn a 2-0 deficit in next Wednesday's second leg at home after twice conceding from mistakes in the opening 35 minutes.
"The way we started the game allowed the opponent to believe and to put us in trouble," Lloris said. "The first half was the image of the lack of aggressiveness but in the second half we showed a good face – a lot of commitment from all the players. We took more risks, we created some good actions and at the end, it's 2-0 down and there's still one game to play.
"We have to believe because in football anything can happen. With energy, with belief, with the help of our crowd, hopefully we're going to deliver a great night.
"After that game, there were some disappointments and also some regrets. The way we started the game is a bit frustrating. Because you are playing a semi-final. At least if you cannot play good football, you have to be ready to fight, compete and be more aggressive than the opponent."
Reflecting on two sloppy goals, Lloris added: "You know when there's a lack of aggressiveness on the pitch, at some moment in the game you're going to pay for it. Unfortunately it cost us the two goals.
"We cannot forget that in front of us is one of the greatest teams in Europe. They won the Champions League last season and they're much in advance of us in terms of process. If we want to grow as a team, we need to learn from that type of performance.
"There was something in the balance – you play a semi-final, there was expectation and unfortunately the first half has to be analysed by ourselves."
Lloris added: "We know when you play two legs, the most important thing is that at the end of the first leg there is still a chance to go through.
"We didn't concede the third goal, unfortunately we could not score that goal which would allow us to believe even more. We know in football you can change a result very quickly with good energy, a bit of luck, good discipline. We have time, we have one week.
"There is still an FA Cup game [against Morecambe] this weekend but it's not over. This is the message. We will need our fans behind us and we'll have to play an amazing game to turn qualification on our side."
