Tottenham paid for not being focused, brave and ready against Newcastle - a lack of mental fortitude captain Younes Kaboul says is unacceptable.
The arrival of Mauricio Pochettino meant this was always going to be a season of transition at White Hart Lane, yet frustration is already beginning to creep in following a disappointing start to the campaign.
Newcastle's 2-1 comeback win on Sunday condemned Spurs to what is already a third home league defeat of the campaign, leading the recently-appointed head coach to fume - not for the first time - about his players' mentality.
It is criticism his skipper accepts, with Kaboul withering in his assessment after Tottenham's latest defeat, especially the way substitute Sammy Ameobi's levelled just seconds after half-time.
"It is very disappointing," he said. "We started the game well and the most difficult task was to score, which we did, and the first half was comfortable.
"We had the ball, took our chance but then it was blackout, straight away.
"We came back on the pitch not thinking, he missed the pass and he went straight away to score. We have to be more brave and focused straight away.
"I think it was five seconds and it shows you at this level there is no mercy, if you're not focused, brave and ready, you pay the bill straight away."
Kaboul insists that complacency was not behind Ameobi's leveller, but a lack of concentration was clearly evident.
"Maybe, that's maybe the word," he said. "Focused and brave - we should not concede goals like that.
"If he scores an unbelievable goal you can't say anything, but from where it started and where it ended, it's not acceptable.
"When they scored the 1-1, it was another game. It was like the first half was last weekend. It disappeared.
"Then we conceded the second one, we had chances to come back 2-2. It was really hard."
The comments from Pochettino and Kaboul about mental strength are similar to those made by former boss Tim Sherwood and goalkeeper Hugo Lloris last season.
So, do Tottenham need more character in the squad? "Maybe, yes," Kaboul said.
"When you concede a goal straight after coming back on the pitch, you need to reply immediately. You need to send a big signal: 'Okay, you scored, but now we're going to reply'.
"We need to be more consistent and regular and more mature on the pitch.
"It's about knowing how to control the game, kill the game, knowing how to defend all together in certain phases of the game and to be more confident, too."
This was another missed opportunity for Spurs, who are already closer to the relegation zone than the Champions League places.
The north Londoners have not appeared in Europe's premier club competition since the 2010/11 season and it is looking like that wait is set to continue.
"Of course we want to [qualify for it] but the most important thing for us this season is to finish as high as we can," Kaboul added.
"We want to improve and we work very hard, trust me, and we want to improve at any point."
Spurs will look to get back to winning ways in Wednesday's Capital One Cup clash with Brighton, while Newcastle will look to continue their upturn in fortunes in their tie at Manchester City.
It has been an unpleasant start to the campaign for all involved with the Tynesiders, yet back-to-back wins have lifted Alan Pardew's side out of the relegation zone.
The wins go some way to alleviating the pressure on under-fire Magpies boss and midfielder Moussa Sissoko is proud of the way they have responded.
"It is good because the start of the season has been hard - we lost or drew too many games," the France international told the club's official website, www.nufc.co.uk.
"We stuck together though. We have worked very hard, every day, and now we are getting our rewards.
"We have great spirit in the dressing room and everyone wants to win games for the club.
"Today, we played very well and it was a good win for the team, for the club, for the fans, for everyone."