Georginio Wijnaldum says Liverpool should have done even better against Tottenham after their 1-0 victory over the north London side.
Roberto Firmino's first-half strike was enough to seal the three points and ensure Liverpool remain unbeaten in this Premier League campaign.
The Reds' 61 points from their first 21 Premier League matches is the best start any team has made to a campaign in one of Europe's top five divisions in the era of three points for a win.
But the clash with Spurs showed that Jurgen Klopp's team still have some work to do, according to Wijnaldum.
“[It was] really tough [physically] but also because I think we made it really tough for ourselves in the second half,” he told Liverpool's website.
“I think first half we played a good game but we gave sniffs away and gave them a little bit of confidence.
"Because it was only 1-0, they had the confidence they could equalise and in the second half you know they will come out and try to equalise. That’s what makes it harder – and also because we didn’t do what we did in the first half.
“I think that was the reason why it was really tough. Normally, it’s always tough when you play against Tottenham but I think we made it tougher than what it was.
“It was only 1-0 so they had the confidence to try to score a goal. We had to do better with the situation. At the end we defended well but in a few bits in the game we gave chances away and we were lucky they didn’t score.”
With 20 wins under their belt in the league, Liverpool are 16 points clear of second-placed Leicester City with a game in hand, while they are a further point ahead of defending champions Manchester City prior to their game with Aston Villa.
And Wijnaldum says their impressive form is a result of their constant hard work in training.
“It is [incredible],” the Netherlands international added.
“But we also work really hard to keep this run going, we have a manager who keeps both our feet on the ground and to work even harder.
“Every day when we are training or playing a game, we try to do it better than we did before. We always strive to do it better.”