A young Igor Thiago could not have known he would one day break the record for the most goals by a Brazilian player in a Premier League season. But the Brentford forward has always had one thing clear in his mind - nothing would stop him from becoming a professional footballer. That is the promise he made to his mother Maria Diva when he was growing up in Cidade Ocidental, a small town in central Brazil.

He has never forgotten the day they went to a family meal where everyone was supposed to bring a dish. Raising four children on her own and working as a refuse collector on a minimum wage, Diva did not have it easy and arrived empty-handed. It was then that Thiago heard a close relative say she would only take her children out to eat at other people's expense. Diva felt humiliated and left in tears. "From today on, no-one in this life is going to humiliate you any more," Thiago told her on the way home. "I'm going to become a footballer, you'll see. Everyone will know me one day." His mother may have thought he did not really know what he was talking about. But he knew.

However, his path to success has not been straightforward. He had to wait until he was 17 to sign for a club, having faced several rejections at trials around Brazil. "Thiago would call me late at night in tears to say that football wasn't for him," Sergio Goncalves, his mentor from his early years at Gremio Ocidental, a local community football initiative, tells BBC Sport. "But he was born to score goals."

The 24-year-old has found the back of the net 16 times in the Premier League this season. He is on target to reach the 20-goal mark once again in his career - having done so in three of his four seasons in Europe, the only exception being his debut campaign with Brentford, which was disrupted by a serious injury.

Thiago's next stop is Saturday's west London derby against Chelsea. Having lost his father prematurely, Thiago found a paternal figure in Goncalves, who mentored him between the ages of eight and 16 - before the striker joined Vere in 2018 then moved to Brazilian giants Cruzeiro a year later.

"People look at him, see how big he is, and think he's that kind of static centre-forward. But he has a lot to his game because of the time he spent in futsal," Goncalves says. "Thiago was born in futsal. It gives you so much dynamism, such quick thinking. A lot of scouts who came through here now call me to say 'Sergio, I missed out on Thiago'".

Thiago did not take long to make an impact for Cruzeiro, going on to score in his senior debut in Belo Horizonte. But that was it. He probably could not have had a more challenging first-team experience. That side is remembered as the worst Cruzeiro team ever - they finished their Serie B campaigns in 11th and 14th place in 2020 and 2021.

"The pressure was everywhere - it affected all the players and the coaching staff. It was a very difficult period for the club - delays in paying wages, problems with transfer ban," former Brazil international Mozart Santos, who had a brief spell as head coach, says. "Younger players tend to feel it more. So one of the reasons Thiago maybe didn't perform better in Brazil was this turbulence."

Such was the situation that Thiago fell into depression, questioning himself and even whether he should continue as a professional footballer. "There are things no-one knows that I went through. I went through a period of depression," he said in an interview with Futebol no Mundo podcast from ESPN. "There were nights when I thought about giving up. Even though I was already a professional at Cruzeiro, I didn't want to know about football any more.

"I just wanted to walk away from all of it and live back in the countryside. What really gave me strength was my mum and my children." At the start of 2022, Thiago told his agents it was time to move elsewhere. Bulgarian champions Ludogorets, who had tried to sign him the season before, returned with another offer and secured a deal.

"In football, a lot of people try to define paths and limits for others. You often see a player going through a difficult period and being labelled as a certain type of player and that label becomes a kind of ceiling. I fight strongly against that," former Ludogorets assistant coach Rafael Ferreira, currently at Atromitos in Greece, said. "I believe everyone has room to grow as long as they're in an environment that allows it. And Igor Thiago fits into a very interesting profile because he has a very strong mentality."

"In his early period, he didn't get many minutes. And what does he do? He asks to play for the second team. He wants to play. That shows you his mentality - not sulking because he isn't playing but looking for alternatives. When you work with that type of player, we usually say the sky's the limit." Thiago's mentality also stands out with his team-mates.

"What I really liked about him was that when he arrived, he was always asking the older players what they thought he could improve. That's what I found different about him, special even," says Cauly, a former Ludogorets midfielder who now plays for Bahia in Brazil. "He already had that worker's mentality, that desire to keep improving. And a player with his physical attributes... we already knew that, one way or another, it had to work out for him as a striker."

It was no surprise that, following only one full season and 20 goals later, he was on his way to Club Brugge in Belgium. "Sometimes he'd get, I don't know, five or 10 minutes in a game, come on and score. It was like he had something about him... as if his energy attracted good things," Ferreira added.

Thiago scored 29 goals in his first and only season with Club Brugge. Brentford then anticipated competition for his signing and paid a club record £30m for him. The forward arrived as a replacement for Ivan Toney, who was sold to Saudi club Al-Ahli.

"I remember he always said his dream was to play in the Premier League. He was always speaking very highly of Erling Haaland. And now, today, he's competing with him for the Premier League's top scorer," Cauly says. "That makes me really happy to see. I'm proud of him. He's someone who truly deserves it - a genuinely good person, with a big heart, and he deserves to be where he is."

With Brazil desperately looking for a number nine before the summer's World Cup, there is a growing expectation head coach Carlo Ancelotti will include him in his March squad. "For me, in this next list - which is the last one before the tournament - he has to be in. If he isn't, then it won't be justice," Goncalves says. "Brazil is missing a proper striker, and I believe this is his moment. And when he gets there, I think he'll make the difference."

"I've already been dreaming about it - the World Cup final, him scoring the winning goal. I'm dreaming."