Tottenham’s players have highlighted the mentality of Arsenal as the difference between the clubs. Dejan Kulusevski and Micky van de Ven poured out their frustrations after Sunday’s 3-2 home defeat in the derby, lamenting the softness of the concessions, in particular.

Two of Arsenal’s goals came on corners – one a Pierre-Emile Højbjerg own goal, the other a free header for Kai Havertz. It is an area of increasing concern for Spurs. They have conceded six times from corners in the past nine games and their record of 14 goals against from set pieces (excluding penalties) is the joint fifth-worst in the Premier League. Arsenal have scored a division-high 22 set-piece goals (excluding penalties).

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Kulusevski and Van de Ven do not believe there is a gap between Tottenham and Arsenal in terms of ability. Spurs hogged 62% of the ball and had 15 shots to Arsenal’s nine, which included a handful of near misses. But in the crunch moments, it was Arsenal – who led 3-0 at half-time – who showed the strength and focus.

“They are much more disciplined and a little bit more mature,” Kulusevski said. “That is where we are lacking at the moment. What do I mean by that? They score on corners. We concede. It is quite easy. It is being strong in difficult moments like a set piece.”

Kulusevski was asked whether that had been the gist of the message from the Spurs manager, Ange Postecoglou, afterwards. “Yes,” he replied.

“It [mentality] is all in life,” Kulusevski said. “That is the only thing that matters – the head. You can be how good you want in football but you’ve got to be strong in every situation. Arsenal have obviously done that in the last period. They fight to win the league. We still have to do that. We are improving in other areas. We still lack a little bit in that part.

“I don’t think it is about ambition. Everybody wants to win but then you have to sacrifice a lot for that. It is a lot. But talking about mentality, do you think it is easy to be down 3-0 at half-time and then go out and play 3-2 against the ones that are first [in the league]? That is also mentality. The second half was unbelievable. We are showing it … it is just that you have to show it for 90 minutes. If not it is difficult. We are showing it in bits but we have to do it much more consistently.”

Van de Ven said Arsenal’s clinical edge had set them apart. Their other goal – scored by Bukayo Saka for 2-0 – followed a quick counterattack that began on the edge of their own box, before a long diagonal ball from Havertz.

“I don’t think in the football part we are worse than Arsenal,” Van de Ven said. “I wouldn’t say we have that problem. But you see their goals and they were ruthless. They took every chance that they had and that makes the difference.”

The game veered away from Spurs after Saka’s goal on 27 minutes. Moments earlier, Van de Ven had been denied an equaliser for 1-1 when the VAR ruled he had been marginally offside.

“If you concede three easy goals, you can play how you want but it’s hard to win,” Kulusevski said. “You can see on their second goal, it is too easy. A long ball from Kai to Saka and it is 2-0. Of course we have to improve on that.”

Van de Ven added: “The first half was not good from us – 3-0 … it can’t happen in your own stadium in a big game like this. I think in the second half we played really well. We pressed up high and we controlled the game. But you cannot concede three goals in the first half at home if you want to be a top team.”

Spurs’ regrets took in how Cristian Romero glanced one header just wide in the 19th minute at 1-0 and hit the post with another almost immediately. But the VAR overrule most aggrieved them. When a Pedro Porro shot hit Takehiro Tomiyasu, the ball ricocheted off Gabriel Magalhães to fall perfectly for Van de Ven. He had been beyond the last Arsenal defender when Porro went for goal. The Arsenal touches were deemed by the VAR as deflections and not deliberate play.

“I really don’t understand the rules in those situations,” Kulusevski said. “I can’t believe it. I was there. It touched two Arsenal players and it is still offside. I don’t know … maybe I don’t know the rules. It was strange. It changes everything from 1-1 [back] to 1-0.

“From the first day they brought it [VAR] in, I was not a fan. I think it’s not as fun for nobody – the fans, the players. But that is a completely different discussion.”