When an 18-year-old makes Real Madrid a historic moment in a pivotal Champions League tie against City, it inevitably draws praise and attention.
In only his first start in the tournament - and fifth game for the team - Thiago Pitarch made a strong impression as the 15-time European champions secured a three-nil last-16 first leg lead at the Santiago Bernabeu.
The teenager, who also had his club debut in the play-off round a month ago with a cameo off the bench at Sporting Lisbon, then assisted the Madrid side defeat the English champions in Tuesday's second leg to secure a last eight place.
Aged 18 years and 226 days, Pitarch was the club's most youthful starter to start twice in the Champions League knockout stages, beating star Vini Jr's record by 10 days.
The midfielder is the most recent to emerge from the famed youth system and is rapidly cementing himself as one of the manager's most exciting protegees.
He signed for Madrid from Leganes in 2023, having previously been with Atletico Madrid and Getafe academies, and starting out for the Juvenil C team, where he rapidly created a positive impact.
He worked his way up to the reserve side and it was during a friendly match in which they faced the senior squad, then managed by Arbeloa, where the youngster is said to have caught the attention of the current Real boss, who took over from the previous coach in the new year.
Reports would later describe the moment as "an instant connection," adding Pitarch excelled not only for his technical ability, but for the vitality, character and determination he brought to the team.
During the summer of 2025, former boss Alonso called up Pitarch to practice with the senior squad and awarded him playing time in the warm-up matches.
Yet, it was the change in manager that became the defining moment in his career as he was introduced as a second-half replacement in each leg against Benfica that led to the meeting with Manchester City.
"I've dreamed of this each night before going to bed, the first day I started playing football, each day you go to train and each day you play a match," said the player following his debut.
"I've just fulfilled my ambition with the best team in the world and in the top tournament."
Given a first start in the Spanish league against his former club - where he was for four years after moving from Atleti in 2018 - he has retained his spot for the next four as fitness issues to Bellingham and Dani Ceballos created an opportunity.
The teenager has seized it with performances that have belied his youth and inexperience.
"He is a very quick player, and you can see his capabilities," remarked the coach. "He is extremely dynamic, with great stamina, effort and mobility."
The player's mindset has also impressed his coach.
"His standout trait is his personality," continued he. "He always wants the ball, and when pressed, he doesn't feel it.
"I understand fans might be astonished to watch him start in a Champions League match, but he is selected because I had total trust in him to do what he usually does.
"Thiago will continue to get chances with the first team. It's a pleasure to have a talent like him."
Pitarch was born in Fuenlabrada, in the Spanish capital's community, and grew up fully immersed in Spanish football, progressing through local academies before joining the club's famous La Fabrica system.
He possesses dual Spanish and Moroccan nationality, giving him the option to represent either country at the highest level.
Under international regulations, footballers may appear for multiple nations at youth level without being permanently tied, with the final decision only binding once they play in a competitive full international.
He has played for the Spanish national team at underage levels, turning out for both the under-19 and under-20 sides, and took part in the 2025 Youth World Cup, where La Roja made it to the last eight.
Nevertheless, he has not yet decided to either full national side, who are watching his progress with keen attention.
In a recent interview, the player said: "I haven't made my final decision yet. Things are positive with Spain, but I'll make a conclusion in the near future."
This scenario echoes that of other dual nationality talents such as Real team-mate Diaz and Barcelona forward Yamal. While teenage Lamine chose Spain, Diaz decided to play for the Atlas Lions.
For now, Pitarch's focus is on making his mark in the Madrid lineup and repaying his manager's belief.
He featured for 74 minutes in the 2-1 victory at the Etihad, which completed a 5-1 aggregate success and a quarter-final matchup with the German champions.
He was replaced by another academy player in Manuel Angel to emphasise the coach's confidence in younger players to help the team chase future success.
Following his impressive impact to date on European football's biggest stage, Pitarch is expected to play a key role in that.
"Arbeloa handles me the identical way. We deal with it very normally. I try not to think about it excessively - I must deserve my playing time on the field," he said after the success at Manchester.