Harry Kane is demanding more maturity from Tottenham and cannot understand why they continue to make the same mistakes as they did in Mauricio Pochettino’s first season in charge after they threw away a two-goal lead at Olympiacos.

Just as at Arsenal this month, Spurs conceded a sloppy goal just before half-time and the Greeks capitalised on the change in momentum to draw the Champions League opener 2-2 .

Pochettino’s XI had an average age of 26.4 and eight were starting their fourth consecutive Champions League campaign under Pochettino, who afterwards accused his players of failing to respect his gameplan.

Kane (right), who opened the ­scoring with a penalty before Lucas Moura put Spurs 2-0 ahead in the 30th ­minute, said: “The hard part to get your head around is we’re not young any more, we’re not inexperienced.

“We’ve all played in big games for club and country. I can see why the manager is frustrated because he’s been here for six years now and we’re still making similar mistakes to the ones we were in his first year. We’ve got to find a way to get around it and improve.

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“I don’t doubt the mentality of the team. We’ve come through a lot in the last few years, including reaching the Champions League final after being down and out in the group. But a bit more maturity will help.”

With Spurs cruising towards the interval and Olympiacos’ infamous Ultras subdued, the turning point came after 44 minutes, when Daniel Podence surged forward and fired past Hugo Lloris. Mathieu Valbuena then won and converted a penalty following a clumsy foul from Jan Vertonghen 10 minutes into the second half.

“Conceding before half-time killed our momentum,” said Kane.

From the beginning we had a plan and we didn’t respect the plan" Mauricio Pochettino, Tottenham manager

“It happened against Arsenal as well. I’m not quite sure how they got through so easily. But especially away from home in the Champions League, you have to knit together, make sure you don’t concede.

“Whether that’s being more compact, going direct and seeing out the clock or something else. At 2-0 up if we see it through to half-time it’s probably a ­different game.

“At half-time, the gaffer said the ­players need to respect their positions more. We tried to do that. I don’t think we did it particularly well all game. Any time you’re 2-0 up away, especially in the Champions League, you expect to go on to win. It was a ­frustrating game.”

Spurs began last season’s European campaign with a 2-1 defeat at Inter Milan and they took just one point from their first three games before recovering to scrape through the group and reach the final.

Kane added: “It’s disappointing because it takes a lot of hard work and energy to get back to the top of the group. We play Bayern, a tough opponent, next. That’s the frustrating part.

“We know how much effort it took to get to the final last year and now ­everyone sees us as a team that can get to the final, so we have to perform even better. Teams will want to beat us.

“The atmosphere was amazing. On the penalty, I couldn’t hear the referee’s whistle. That’s why it’s frustrating because when you go 2-0 up, you quiet them. But the goal before half-time got them behind their players again. That’s what really hurts.

“It feels like a loss. We need to make sure we take care of our home games and pick up results away as well.”

Pochettino admitted he was “very disappointed” with his team’s display. He added: “In the first half, I wasn’t happy. From the beginning we had a plan and we didn’t respect the plan .

“That’s what disappointed me the most. I told them at half-time. We scored two good goals but if you analyse the performance only, it wasn’t great.

“We conceded a lot of chances and the way we conceded the first goal was so painful