As Jude Bellingham waited to be spoken to by the British media, pitchside at Signal-Iduna Park on February 17, disappointment was written all over his face.
Though the midfielder had both scored and assisted a goal on his side's return to European action following the winter break, an otherwise drab performance had seen them beaten 4-2 at home by Rangers, leaving their hopes of winning the Europa League in tatters.
"We can’t allow those kind of chances," Bellingham began to BT Sport, "but there’s a bit of hope because there’s a second leg, and there’s not one person in that dressing room who will give up, because I won’t let them.”
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The clip soon went viral, with fans amazed at the apparent leadership that was being shown by an 18-year-old inside the dressing room of one of Europe's elite clubs in a foreign country.
The words "future England captain" were a recurring theme among Three Lions supporters who posted it to their own social media timelines, and there will have been plenty of current and ex-professionals who would likely echo those thoughts.
While Bellingham's drive to win and willingness to not hold back his feelings can get him into bother - either with his own team-mates, as reportedly happened after his foul-mouthed tirade at team-mate Nico Schulz in the return leg at Ibrox, or with the authorities, who fined him €40,000 in December after he questioned the integrity of referee Felix Zwayer given his previous links to match-fixing - they are a sign of a confidence that has been with him since his days as a fresh-faced teenager at Birmingham City.
"When I first saw him live at a Birmingham City Under-23s game, he was still relatively slight and physically average at best," Dortmund's chief scout, Marcus Pilawa, told GOAL. "So he didn't stand out because of his physical abilities, but because he was the captain and already exuded the sense of responsibility on the field that we see here with us now.
"In other words, he took on incredible responsibility, had charisma and personality, was courageous and fulfilled certain leadership criteria. He had a feeling for how the game has to be ordered in central midfield and an incredible work rate."
It is those attributes that laid the foundations for Bellingham to become one of the leading midfield talents in world football, and helped earn him the NXGN 2022 prize as the best male footballer born on or after January 1, 2003.
It is likely to be the first of many global honours for Bellingham, who has already broken countless records at both club and international level, and was named Bundesliga Rookie of the Year for the 2020-21 season.
The global acclaim that Bellingham is receiving is all a far cry from his early years living in Stourbridge, a town around 15 miles outside of Birmingham city centre.
It was there where was spotted by Birmingham City as an U8s player, and where that drive to succeed and better himself was cultivated.
Once in the Birmingham academy, he would stay late after training to hone his skills, and asked coaches to play him in different positions during matches so as to improve his all-round game.
By the age of 14 he was playing for the club's U18s, while just a month after his 16th birthday he was afforded a first-team debut by manager Pep Clotet, making him the youngest player in Birmingham history. A few weeks later, he added the youngest goalscorer in team history to his CV.
"When he started playing with the senior team, he fitted in because players recognise good players," Mike Dodds, the head of the professional development phase programme at Birmingham, told GOAL. "If you go into a first-team environment and you're a good player, there's a respect there.
"I think once he got the opportunity in the first team, the players thought 'this boy is decent', and that's why he fit in so well. When they saw they could trust him, they forgot about his age. He just becomes another player.
"Once you've got the combination of being a good player and being able to trust them, then age becomes irrelevant. When you put players of that age in that environment, they can surprise you."
Surprising both his own coaches and opposition managers is exactly what Bellingham set about doing, as he made 44 first-team appearances over the course of the 2019-20 season, scoring four goals in the Championship as he took the English second tier by storm.
"In my view, he has to fight to become the most complete player in the game," Clotet told The Athletic following the culmination of that campaign, with the Spaniard having left the club a few weeks earlier.
"He has everything in his hands to do it. He can touch the sky as a player - he has no roof.”
That was something Europe's biggest clubs were starting to learn, too.
In truth, given his performances for England's age-group sides through the years, he was on their radars already, as Manchester City, Bayern Munich and Barcelona all made their interest known to Birmingham before Bellingham had even made his senior debut.
Arsenal and Manchester United joined that chasing park as the season progressed, but it was Dortmund who won the race, paying €25 million (£23m/$29m) for a player they had been tracking for the best part of three years.
"He caught our eye as an England U15 international at the end of 2017, and we then followed him again at the other internationals three months later,” Pilawa said. “There, the good impression (he had made) was more than confirmed, and we saw him get even better. From then on, things took their course.
“We were among the first to get hold of him, and wanted to get him on his 16th birthday, when he was still the small, lanky player. We already believed in him then, and not just when he played in the Championship.
“We built a good relationship of trust with his family, his management and him. We gave him a clear plan and a profile of his strengths and weaknesses, where and how we see him fitting in, and why his profile fits us and the composition of our midfield.
“We told him: ‘You will have a lot of competition in terms of quality of players, but your advantage is that we don't have your profile in the squad, so you will definitely get playing time with us’.
“At Birmingham, he was also used on the right-hand side and as a nine-and-a-half. But we told him: ‘You are not a six or a winger with us, you are clearly our eight’. In the end, it was a damn tough fight because the competition for him was immense.”
'Immense' is a good word to describe the reaction to Bellingham's departure, not least due to Birmingham's decision to retire the No.22 shirt of a teenager who had spent just a single season in the senior ranks before leaving.
Criticism and mocking jokes rained down on both the player and his boyhood team, but Birmingham knew that the greatest talent that the club has ever produced, and perhaps a footballer who one day will be - if he is not already - regarded as the best player to have ever worn the their blue shirt, had just departed St. Andrew's.
Bellingham wasted little time in silencing the doubters, netting on his Dortmund debut to become the club's youngest goalscorer, in what was the first of 45 appearances in all competitions during his first season of top-flight football.
“We were reasonably sure that he would get enough playing time in his first year. But I admit that we didn't know how confidently he would handle his situation,” Pilawa explained.
“There was Covid, the gruelling Championship season until the end of July and the mental strain of the relegation battle with Birmingham. He only had seven days off as a young lad and then arrived here with no holiday and a bit of the pressure of the high transfer fee.
“So there could have been problems at the start of the season, but he surprised us there as well. We wanted to give him more breaks, but he didn't want them.
“He is just so clear in his head and has such a strong personality, that in the end his development almost did not come as a surprise. But, initially I thought he would only be involved fully in the second half of the season.”
Ten of those games came in the Champions League, with his performances against Manchester City in the quarter-finals showcasing to an English audience just how at home he was at the very highest level of the game.
"I can't believe it, maybe he's a liar!" Pep Guardiola exclaimed when asked about Bellingham's performances against his side. "He's so good for 17 years old, he's a fantastic player.
"There was one moment when he didn't get the ball from central defenders, how he shouts and demands that ball get to him at 17 means a lot."
A part of England's squad as they reached the final of the European Championship in 2020, Bellingham became the youngest player to ever appear in a knockout match at the finals.
Clearly not the "small, lanky player" that Pilawa first scouted four years previously, he was now a physically imposing man, and in 2021-22, he has taken his game to a new level as a result.
He has already bettered his best-ever goalscoring season, and is well into double figures for assists across all competitions with two months of the campaign still to go.
He netted one of the Bundesliga's goals of the season against Arminia Bielefeld in October, and has a relationship with Erling Haaland that a number of top clubs from around the continent would love to have replicated at their own stadiums in years to come.
Where exactly Bellingham will play next remains up for debate.
Liverpool are routinely linked with him, with his all-action style in-keeping with what Jurgen Klopp demands of his players; Chelsea were interested in signing him in the summer of 2021; and Manchester United would love for Bellingham to take the same path as Jadon Sancho and swap Westfalenstadion for Old Trafford.
Red Devils legend Rio Ferdinand has already described the teenager as a "future Ballon d'Or winner", and there are sure to be teams on the continent who are desperate for a player of Bellingham's talents to join them. Whether they can compete financially with the Premier League's biggest and best, though, is unlikely.
Regardless, Bellingham has both the ability and self-confidence to make good on the promise he has been showing for more than just his three seasons of first-team football.
He will not give up on reaching the very top. He will not let himself.
Previous reporting by Ronan Murphy.