Mauricio Pochettino keen to keep happy dressing room after Dani Osvaldo mistake
Mauricio Pochettino will not risk Tottenham's dressing-room harmony after learning from his "mistake" in signing Dani Osvaldo at Southampton.
Spurs boss Pochettino has effectively distanced himself and the north London club from a January deal for West Brom striker Saido Berahino - a long-term target - in highlighting Osvaldo's unsettling stint at St Mary's.
Osvaldo was suspended by Southampton for two weeks for headbutting Jose Fonte in a training-ground bust-up in January 2014, with three loans then preceding his August 2015 departure.
Berahino has cut a divisive figure at West Brom and Pochettino's desire not to wreck Spurs' happy camp hints at a cooling of interest in the 22-year-old.
"I can tell you now in this case I think it was our mistake, because of what he showed in the problem with Jose Fonte," Pochettino said of signing Osvaldo at Southampton. "I think in this moment you realise it was a mistake.
"I can recognise, and Osvaldo, to be fair, he recognised it was a big mistake for him to come and for us to sign him. But I am very honest about this.
"For discipline and good behaviour, it's important players are always kind with team-mates. It was unacceptable behaviour, and for that we were very strong with him.
"Football is a big, big world and it's impossible for a manager or people in football who make decisions to say they have never ever made a mistake. Anyone saying that is a big liar.
"You've got to improve and learn from that, to make sure you don't repeat those mistakes.
"It's a consequence of our decisions that we have a good dressing room at Tottenham now, because it's not magic.
"We have a very good changing room now but we've worked very hard to try to build relationships between the players and the staff to create a very good level of training, discipline and mentality. And this is important to keep now.
"The most important thing now is to settle and to grow in this idea that we need to work hard, have a good mentality, respect and discipline. This is the most important thing for the future."
Berahino threatened to go on strike after West Brom refused to sell him to Tottenham in the summer, creating a sizeable rift with chairman Jeremy Peace.
Taskmaster boss Tony Pulis has continued to clash with the Burundi-born goalscorer as the campaign has unfolded.
Both Spurs and Newcastle have been tipped as preparing January bids for the highly rated forward, but Pochettino has vowed to remain hugely discerning on the type of characters Tottenham will recruit.
"If you bring someone who is a normal player, and not a good man, then you do it for what? It's bringing them for the sake of it," Pochettino said.
"You need to bring the right profile and quality enough to help us and improve the squad."
Pochettino insisted Tottenham would only now consider spending £30million on one player if that target could instantly become the club's biggest star.
"For me when you spend more than 15 to 18 million, first you need to bring good things, like good behaviour, responsibility, discipline, professionalism," the Argentinian said.
"Then he should have enough quality to improve the squad, that's very important.
"If we spend 20 to 30 million, we need to be sure this type of player represents a (Gareth) Bale or (Cristiano) Ronaldo for Real Madrid, or (Lionel) Messi or Neymar for Barcelona.
"We need to speak about the player that is our best player, and needs to help us achieve a lot of things.
"It's impossible to sign a player for this amount and need to wait for performances. It's impossible."