Tottenham coach Juande Ramos has warned his defenders he will bring in new blood this month unless they stop gifting goals to the opposition.
Spurs have been vulnerable to set pieces in recent games and conceded two more goals in that fashion when beaten 2-1 by Aston Villa yesterday.
A header by Olof Mellberg and a similar effort from Martin Laursen from a free-kick and corner respectively sealed victory for Villa either side of a Jermain Defoe effort.
It means Spurs have now let in seven goals during their last three Barclays Premier League games.
Ramos said: "We need to find a solution to these defensive problems. If we can't sort the problems out with the players we already have here, then we will look outside for other players.
"We are lacking in some defensive departments and it is something we need to look at. We are paying dearly for those lapses.
"In the past few weeks we have made it a habit to concede goals from set pieces and it is hard to win matches when letting in so many goals in that way."
Ramos also insisted that Tottenham intend to try to hold on to star striker Dimitar Berbatov amid speculation linking him with Chelsea and Manchester United.
His agent Emil Dantchev has already said the Bulgaria international would like to leave Tottenham if a club came in for him that matched his own ambitions.
But Ramos said: "Obviously Berbatov's agent is looking to do his business and has been making comments.
"But we are happy because we have the player on a contract and we plan to keep him."
Ramos also defended his decision to leave leading scorer Robbie Keane on the substitutes' bench until the second half.
He said: "We have to vary the squad. We have a lot of matches coming up and it was Robbie's turn to be omitted from the start."
Villa again showed their own ruthlessness at set pieces and have scored more goals from dead-ball situations than any other team in the Premier League.
The goals from Mellberg and Laursen mean 18 of their 37 goals this season have resulted from either a corner or a free-kick.
Villa manager Martin O'Neill said: "Set pieces are a big part of the game. Big matches are decided by them. If we get one, we have players who can deliver a good ball into the area such as Ashley Young. They invite people to attack the ball.
"Martin Laursen has proved himself to be a handful in those situations. He goes for the ball and is so determined and he's come up with another big goal for us."
Laursen, who is out of contract in the summer, came in for praise from O'Neill for another rock-solid defensive performance against Berbatov who had little chance to add to the four goals he had netted against Reading at the weekend.
O'Neill, who intends to strengthen his squad during January, said: "Martin was a colossus against Tottenham - but he has been all season to be fair. Against one of the best centre-forwards in Europe his performance was magnificent.
"He has also got this great knack of scoring goals and is playing like a man possessed."
Boss Ramos wants Berbatov to stay with Spurs
Tottenham coach Juande Ramos has reiterated his determination to keep hold of star striker Dimitar Berbatov.
The Bulgarian international is already being linked with a host of clubs, including Chelsea, Manchester United, Real Madrid and AC Milan, since the opening of the transfer window.
His agent Emil Dantchev claimed the 26-year-old would like to move to a club which matched his own ambitions, but Ramos said: "Obviously Berbatov's agent is looking to do his business and has made his comments. But we are happy because we have the player on a contract, and we plan to keep him."
Ramos admitted he will look to bring in new defensive blood unless Tottenham can cut out the kind of lapses which cost them both goals in the 2-1 reverse against Villa from set pieces.
Olof Mellberg opened the scoring from an Ashley Young free-kick and, after Jermain Defoe had equalised, a corner from Gareth Barry was headed in by Martin Laursen for the winner.
Ramos said: "I am not happy because we have come back from a goal down, created chances, and still lost. I think a draw would have been a fairer result.
"But in the past few weeks, we have conceded goals from set-pieces, and it is hard to win matches conceding as many as we do from those sort of positions.
"We are lacking in some defensive departments, and it is something we need to look at. We are paying for lapses.
"We need to find a solution to our defensive problems. If we can't sort the problems out with the players we already have here, we will look outside for other players."
