LONDON -- Mauricio Pochettino said he felt "embarrassed" and "ashamed" by Tottenham Hotspur's 1-0 defeat to Bayer Leverkusen in the Champions League.
Kevin Kampl's second-half goal condemned Spurs to a second consecutive home defeat in the Champions League, in front of a club record attendance of 85, 512 at Wembley Stadium.
The defeat leaves Spurs winless in six games and without a goal from open play in five, while Pochettino admitted they must beat CSKA at the national stadium and win in Monaco to have any chance of reaching the knockout stages.
Asked if playing at Wembley was affecting his team, Pochettino told a postmatch news conference: "Is there a better place to play football than here? Tell me one place better? That is impossible to find somewhere better than Wembley, with the history, where football was born and if you don't show your real quality then it is a big problem, it is our problem.
"We were the problem, not Wembley. We are very disappointed with our quality, that is the problem. Please stop blaming Wembley.
"The problem is inside us. There was 85,000 people supporting us today, like against Monaco. I feel a little bit ashamed, it is embarrassing for me, but for the players as well, they feel the same. We need to find the solution, we need to find. We have time, yes. We need to win two games, yes.
"We had the possession but we need to create more. Today there's no excuse, after two games, Monaco and Leverkusen, they were clinical in front of the goal, we weren't which is why we lost the game.
"We must win, if not forget Champions League. We have to win against Monaco and CSKA. That is the truth that we have to win both games, if not bye, bye Champions League."
Tottenham face Arsenal in the North London derby at the Emirates Stadium on Sunday, with the Gunners unbeaten in 14 matches since the opening day of the season and fresh from a brilliant comeback at Ludogorets that sealed their progression to the last-16.
Pochettino said his side need to improve and admitted the Spurs squad was facing a challenge of balancing the twin demands of the Premier League and Champions League.
"Of course we need to improve, we don't have a lot of time. We need to be critical and put ourselves in front of the mirror and say 'come on, we need to improve.' We need to be realistic in our analysis and that is very important," he said.
"To find the answer that is inside us, that is very important. We were poor today and both games we have played at Wembley we haven't shown our real quality, for different reasons, but we need to find out why.
"Maybe it is one of the reasons to manage both competitions -- two of the most tough competitions, the Premier League and the Champions League. That was the first experience for I think 90 percent of the players. It is good to see how we react every week, two games. It is good to assess for the future, it is a positive thing. It is maybe one of the reasons that we need to be critical and analysis."
Pochettino confirmed that Mousa Dembele had asked to be substituted in the first half after twisting his ankle, and said Harry Kane "might be available" for Sunday.
Bayer Leverkusen boss Roger Schmidt said: "Perhaps there was a slight advantage to play here, rather than White Hart Lane, because it's not their ground. But in terms of atmosphere it was very good here, at times. But I think that was partly reduced by the way we approached the game, pressing early on and asserting ourselves on the match.
"We have to remember that Tottenham were unbeaten in the league, which makes this even more special."