Tottenham boss Mauricio Pochettino admitted his side showed a lack of fight in their 2-1 defeat at Leicester.
Spurs have won just one of their last six Premier League matches and have lost as many this season as they did throughout the whole of last term.
Pochettino has faced some criticism over his tactics and team selections, but the Argentine insisted they were not the reason for his team’s problems.
Speaking at his post-match press conference, Pochettino said: “It’s frustrating. It’s not to talk about tactics or different systems or the selection and the starting 11, it’s about that, collectively, the performance was so poor.
“In football you must first of all compete, fight and be focused – and then your quality will appear.
“Leicester showed more (fight) than us. We were poor and this is so disappointing. They were more aggressive than us.
“We need to learn from this game. We need to start every game with the idea that we fight and compete. If you don’t compete and fight in the Premier League then the gap in the quality is even.
“You cannot afford to not fight or compete. In the Premier League if you don’t fight first and compete, you will struggle.”
The defeat left fifth-placed Spurs 13 points behind leaders Manchester City.