Tottenham Hotspur manager Mauricio Pochettino says the players' lack of concentration proved fatal as they went down 2-1 to Newcastle United.
Sammy Ameobi restored parity for the visitors only seconds after the start of the second half, a goal described as a shock by the Argentinean.
"We need to analyse the first half, it was very good, we deserved more than the one goal.
"It is difficult to explain how we started the second half, it was a stupid goal.
"It was a shock, all changed after this moment, six second before the stadium had good energy but after this moment our head had gone.
"It was a lack of concentration for us and we need to work on our mentality because it is not a physical or a tactical thing. It is our mentality and our challenge to improve.
"We need to be stronger like a team. We need to speak and create a different situation on the training ground. We need time to work in this area.
"Newcastle is a big team but when you analyse the game, after 45 minutes it is impossible to say we are going to concede a goal like that.
"I think it was the best 45 minutes we have played. It was a lack of concentration which made all the difference."
The defeat, the fourth of the season, see Spurs fall to eleventh in the table, five points from fourth-placed West Ham United.
