Kyle Walker-Peters believes he has already faced the toughest mental hurdle of his career even though he is just 21.

The right-back was handed his first Champions League start in dream circumstances as Tottenham went to the Nou Camp trying to secure their progression to the next stage.

But it quickly turned into a nightmare as he was robbed of possession inside the opening 10 minutes by Barcelona forward Ousmane Dembele, who raced clear and scored.

He later picked up a booking and then was sacrificed in the second half as Spurs chased an equaliser that ultimately secured a last-16 tie against Borussia Dortmund.

It came just 24 hours after signing a new five-year contract and Walker-Peters believes producing such a high-profile mistake will be as tough as it gets in his career.

"I learnt a lot about myself," he said. "Two seconds after making the mistake, I was thinking, 'You know, make sure you don't die on the pitch!'

"But I think I went on to actually play quite well. I think I've got a good amount of mental toughness, to be able to do that. But again, it's all a learning curve for me.

"Especially coming in the Champions League, in a stadium like that against such a good team. To be able to look past that... also with the help of my team-mates straight away.

"Danny Rose came straight over to me and said, 'Keep going'. Harry Kane as well, he said a few things to me. As we went to take the kick-off he just said, 'Keep going. There's plenty of time'.

"That gave me confidence and that's why I went on to play quite well.

"It's always going to happen once in your career. Now it's happened I feel like I know how to deal with it. If it ever happens again – touch wood it doesn't – I'll know how to respond."

With Kieran Trippier having to manage a groin problem and Serge Aurier also suffering from injury, Walker-Peters could get plenty of game-time as Spurs' punishing fixture schedule continues.

Boss Mauricio Pochettino admitted Walker-Peters is a full part of his squad and he could get the nod in Wednesday's Carabao Cup game at rivals Arsenal.

"If I get the opportunity, of course I'd be buzzing to play in the north London derby," he said. "I saw another young player do it a few weeks ago – Juan (Foyth) – and he did really well.

"If I get the opportunity, I'd be really buzzing. All I can do is appreciate that (Pochettino's comments).

"That starts on the training pitch by showing him every day that I'm willing to keep working, keep improving. Those words from the gaffer always help, especially as a young player hearing your manager has faith in you."