Tottenham conceded two more goals away at Norwich City in Saturday's draw and Jose Mourinho said they must cut out the errors.
Jose Mourinho has admitted to being "frustrated" by the number of individual errors being made by his Tottenham players after they drew 2-2 at Norwich City.
Tottenham twice fought back from a goal down to salvage a point against the Premier League's bottom side in Saturday's clash at Carrow Road.
Mario Vrancic capitalised on some slack defending to give Norwich an 18th-minute lead and Teemu Pukki had one ruled out by the video assistant referee for offside.
Spurs improved after the break and equalised through Christian Eriksen's free-kick, only for Toby Alderweireld's clearance to hit Serge Aurier and trickle in for City's second.
Harry Kane rescued Tottenham with a penalty seven minutes from time on his 200th Premier League appearance, but Mourinho was not happy with what he saw.
"I think the same defensive mistakes we made in the first half, we made in the second half. This is being a little bit of our history," he told Sky Sports.
"We started very, very well and had three or four big chances at the beginning of the first half and conceded two very bad goals - one of those offside.
"I have lots of work to do but it has been difficult because I always say you have to try and hide your fragilities."
Tottenham have conceded 12 goals in eight league games since Mourinho replaced Mauricio Pochettino and have kept just one clean sheet on their travels in 2019.
"We have to improve defensively because there are too many individual mistakes," Mourinho added.
"That's very frustrating because we play well and cannot be more offensive than we were in the second half. Our defensive mistakes are match after match."
Eriksen was handed a first start since November and left his mark on the game by scoring his eighth direct free-kick to cancel out Vrancic's first Premier League goal.
The Denmark international's contract expires at the end of the season and he has been strongly linked with a move ahead of the January transfer window.
Mourinho praised Eriksen for his display against Norwich but was unwilling to discuss the playmaker's future.
"I don't want to speak about it," he said. "We are so open with one another. We keep it to ourselves, and I obviously I share it with my boss. But its just between us.
"The only thing I can say is he is trying to help the team and I am happy with his man of the match."