“I just want to have my name out there to the point where when someone hears it they know instantly who is being talked about,” says the Chelsea full-back Chloe Sarwie. “I want to be that player who can amaze people constantly and that is up there as one of the best.”

You could be forgiven for viewing this level of confidence as arrogant, but you would be wrong. The talented 17-year-old defender comes across as grounded, intelligent, hard-working and humble, but her edge is a steely belief in her football.

Sarwie is speaking to the Guardian shortly before signing her first professional contract, four months after her debut in the 1-1 draw with Twente in the Champions League and three months after her first call-up to the England Under-23s.

Sarwie is back with the under‑23s for next month’s games against France and the Netherlands, one of two 17-year-olds considered good enough to compete alongside those vying for a chance in the senior side (the other is Erica Meg Parkinson, who plays her club football in Portugal). Last summer, at 16, she was in the squad that competed at the Under-19 Euros in Poland. “I was taken aback and I didn’t really have any expectations so it was incredible,” she says.

“It’s honestly a really intense environment and every training session everyone just wants to one-up each other. It gets really competitive and just being around that wanting-to-win group was incredible.”

Her Chelsea debut in October, when still 16, came as a surprise. “As soon as I got the nod from Sonia [Bompastor] that I’d be coming on for Sandy [Baltimore] and making my debut, I was just down on the sideline, shocked but pumped and ready to get on the pitch,” says Sarwie, who entered the fray against Twente in the 73rd minute.

She impressed instantly, playing with an admirable fearlessness. “Honestly, when I stepped on that pitch, I didn’t know what to do, I didn’t know how to play, but I was just trying to play my part for the team, fit in and see what I could do. Towards the end of the game, I was being myself a bit more and the more playing time I’m getting, the more I’m able to express myself, but my full self hasn’t come out yet.”

Chelsea are well equipped at right-back, with two of the world’s best in Lucy Bronze and Ellie Carpenter at their disposal, but at left-back there is a hole. With Baltimore performing well in the position but naturally a more attacking player and Niamh Charles out with an ankle injury, there have been some opportunities for Sarwie, against Crystal Palace in the FA Cup and West Ham and Tottenham in the Women’s Super League.

Should her development continue at its accelerated pace there is also the chance to stake a claim in the senior England squad that has had question marks at left‑back under Sarina Wiegman. London City Lionesses’ Poppy Pattinson is the latest to receive a call-up with an eye on finding a solution to the conundrum.

Sarwie was introduced to the Chelsea senior side in pre-season. It was “quite exciting but also quite nerve-racking”, though training and playing with the first team has been hugely beneficial. “It’s a great challenge and I love being challenged and going up against these players, seeing how their level compares to mine and how I can get to that level,” says Sarwie.

“Obviously, Lucy’s at England as well and being able to have that connection is great, even though I’m in one of the lower age groups because, ultimately, I’m learning how I can then progress to that next step and be part of the senior squad. That’s where she can give me tips and show what it takes.”

Sarwie began playing football in the park on her own, light on her feet thanks to ballet from the ages of two until eight. “I used to turn up to ballet with muddy tights after playing football and rolling around in the mud for a good hour or two. But ballet had a big impact on my journey as a football player as my dribbling playing style kind of links back to it. Ballet made me light on my feet. I also had to adapt from a ballet mindset, from a solo stage, to a football mindset and a team performance stage.”

It was in the park where coaches would approach her and tell her she should be playing for a club and eventually she thought: “Why not?” After a season at Millwall, she had trials at Arsenal and Chelsea and had offers from both. “I had to pick Chelsea because it was closer,” she says. “I let my family down on that one because they’re all Arsenal supporters, but oh well.”

She juggles playing and training with studying for her BTec in engineering and her mum, Jean, who is a teacher at her school, is the force that has enabled her to pursue football. She takes her laptop everywhere, to catch up with coursework, with one day a week spent in the classroom.

Sarwie is having to contend with an influx of information. “It’s mad trying to switch the brain from studying engineering to football and back,” she says. “I’m still taking in everything in relation to the first team. I have all that information coming at me and then I have to go home, switch off and then do my work and it’s all a bit chaotic.”

On the pitch, there is also a balance to be struck between what is being asked of her and instinct. “Sometimes on the pitch I can be quite hesitant because I’m trying to think about what I should do at that moment instead of what I want to do, because that’s sometimes two different things. The coach wants me to do something but I want to do something else in the moment and it’s about quickly processing which one I should do.

“Every day I’m getting new information coming in and I’m just trying to soak that up but trying to show myself on the pitch and putting those words into actions on the pitch can be quite difficult and it’s going to be like that for a while because of my age.

“Once I’m on the pitch I just want to be my most relaxed self. Breathing techniques on the pitch really help me stay calm and I’ve been told I look arrogant doing this, but chewing gum on the pitch makes me relax as well.

“I want to be that person that looks in place and calm with the rest of the team, that calms that team down. I don’t want to be nervous when I get the ball, or for them to be nervous when I get the ball, I want to get the ball and to express myself as much as possible with it.”