Tottenham head coach Mauricio Pochettino will not be rushed into buying a new striker, admitting he has learnt his lesson from previous mistakes.
Pochettino is in the market for a back-up striker to support White Hart Lane favourite Harry Kane, but the Argentine is unwilling to be pressured into making ill-judged signings.
The 43-year-old signed controversial striker Dani Osvaldo for a club-record £14.6million during his previous stint at former club Southampton - a move ended after the Italian forward was involved in a training ground bust-up.
And Pochettino says he will only recruit players who match the club's blueprint.
"Any managers or people in football who say they have never made a mistake are big liars," Pochettino said.
"Looking back, it was a mistake. Osvaldo recognised it was a big mistake for him to come and for us to sign him. You know the problems, what happened with Jose Fonte.
"We took the decision to pull him out of the changing room because I have to have discipline. His behaviour was unacceptable and for that we were very strong with him.
"I've been asked about Gareth Bale. He is a player that is welcome in the changing room because we know him. Or if we had the possibility to sign Lionel Messi or Neymar -- it's impossible to say no.
"The problem is if you bring in a player who is normal but not a good guy. For what? We don't want to bring in players for the sake of it. They have to have the right profile."
Tottenham have been had their fingers burnt in the past with big-money signings, most notably the recent £27m acquisition of former Spain striker Roberto Soldado.
Pochettino is determined to use the club's money wisely in the transfer market and says he expects star quality for significant expenditure.
"For me when you spend more than £15m, £16m, £18m you must have a player that brings good things: good behaviour, discipline, responsibility, professionalism," he said.
"It's important to get it right. If we spend £25m or £30m we need to be sure this player can have the kind of impact that Gareth Bale or Cristiano Ronaldo has on Real Madrid. Or Messi or Neymar for Barcelona.
"He'd have to be our best player. It's impossible to sign players for this amount and wait for his performance."