Tottenham Hotspur have frequently spoken about the need to tighten up their leaky defense over the last few weeks but striker Harry Kane said it is time to put words into action after they coughed up early goals again on Sunday.
Liverpool were 3-0 up inside 15 minutes at Anfield and while Tottenham pegged the hosts back to 3-3, Diogo Jota's stoppage-time goal earned the Merseyside club a 4-3 victory.
Spurs conceded five in the opening 21 minutes of a 6-1 rout at Newcastle United and fell behind after only seven minutes in Thursday's 2-2 draw with Manchester United.
Kane said their performance in the early stages of Sunday's game showed they had not learned their lesson.
"It's not the first time it's happened this season. We need to start understanding big games better," he told Sky Sports.
"We've shown we can come back into games and to do it here away at Anfield shows what we're capable of but to have the starts we have had are hard to put into words and are unacceptable.
"There's only so many words you can use, the bottom line is you need to go out there and show it isn't that case."
Interim coach Ryan Mason said the players had to be ready from the first whistle.
"If you're not ready to start games with full intensity you're going to concede goals and to be 3-0 down after that time is hard," Mason told the BBC.
"The manner in which we concede the last goal makes it impossible to take. I need to speak to the players on that, we need to address it and do it quickly."