Tottenham manager Andre Villas-Boas expressed his concern at the display which saw Norwich secure a 1-1 draw at White Hart Lane on Saturday.
Spurs are yet to claim their first win of the season after an opening day loss to Newcastle and a disappointing home draw against West Brom.
New signing Moussa Dembele made the perfect start to his career as a Tottenham player when he found the net in the 68th minute but Norwich levelled with just five minutes remaining to secure a valuable away point.
It was the second time in a week that Tottenham had conceded a late equaliser with James Morrison and Robert Snodgrass denying a first competitive win for Villas-Boas.
The former Chelsea manager was unhappy with the performance of the side as he felt they failed to concentrate for the full ninety minutes.
"This was a different game, we didn't play as well as last week," Villas-Boas told the club's official website after the game.
"It's a pity because we fought hard in the second half, mainly because the first half was poor and we looked a little sloppy in our passing.
"In the second half we improved. Our players really wanted to get the win, they have worked hard so they deserve it.
"We got the goal but again, we conceded in the last minutes so we have to improve on this sharpness, this reaction, this concentration.
"We have to assume responsibility for what is happening, which is disappointing, but everybody inside the dressing room feels if we get the win that we need, it will be the boost we need to take this through."
Villas-Boas will now have some time to work with the squad, due to the international break, and will hope that he can secure his first win of the season when Spurs take on newly-promoted Reading at the Madejski Stadium on Sunday 16 September.