Video: We're conceding too many goals - Mourinho
Jose Mourinho has acknowledged Tottenham's repeated defensive errors must be a great source of frustration for the team's forwards.
Spurs twice rallied from a goal down to draw 2-2 at Norwich City on Saturday, with Harry Kane's late penalty cancelling out a Serge Aurier own goal.
Mistakes in defence have punctuated recent matches, with Paulo Gazzaniga at fault in an ill-tempered London derby defeat to Chelsea just before Christmas.
Mourinho is happy with his forwards and with Tottenham's attitude, yet "ridiculous" concessions continue to irritate him and, he suspects, his players.
"Four matches away, we won two, we lost one and we drew one," Mourinho said ahead of the trip to Southampton. "Is that better than before? Yes. Is that perfect? No.
"If you come [to Norwich] and we cannot create, Norwich dominates us. [Then] we have to defend, we defend well, we resist, you draw 0-0, maybe you have to admit [it is] a positive result.
"The problem is the way you concede goals and the way you play. We go to [Manchester] United, the first goal is a bad goal to concede, we react, we equalise, we get to half-time at 1-1, the second half starts and we concede a ridiculous goal, too.
"That is the problem. We play so well, we create so much and [we do not always win].
"We have to improve. We concede too many goals and it's very frustrating. If I was one of my attacking players, I'd be very frustrated that behind we are not able to stop it, so it's frustrating.
"But it's also a great feeling to know the team never gives up, that even in the most difficult circumstances, we go and we go and we go and we go and we go. So I want to praise that fantastic spirit."
Meanwhile, the head coach, who has typically favoured physically imposing squads throughout his managerial career, suggested Spurs were helpless to prevent certain set-piece shortcomings.
"In the beginning, we were conceding lots of goals on corners. We stopped that," Mourinho said. "The other day, we conceded against Brighton on a lateral free-kick. But in football, there are things that are very difficult to control.
"And when I am small and you are taller than me by 15 centimetres, there are things in football that are impossible.
"The only solution is when you select players and you make squads and teams, you select a majority of tall players to cope with the physicality of top football either in the Premier League or European competitions."
A wider defensive fix will come in January, Mourinho hopes, but time on the training ground will be treasured over mid-season signings.
"No, no," he reiterated when asked of transfer business. "In January, we have a little bit more time to work, and we are going to try to improve."