Arsenal unearthed a 'diamond' when they found Gabriel Martnelli lighting up the Brazilian fourth division as a teenager.

The young forward, 21, has taken a circuitous route to stardom, but the talent and commitment to be a top player has always been there and this season, in a reinvigorated Arsenal team, he is surely set for his best year yet.

He got off to the perfect start with a goal 20 minutes into the new season away at Crystal Palace, to lay the foundations for a 2-0 win.

Gabriel Martinelli recovered from an early miss to put Arsenal ahead in a win at Crystal Palace

Despite the plaudits, the international call ups and rising salary, Martinelli is as focused as he was the day he arrived at Arsenal in July 2019, aged just 18.

With 85 appearances, 19 goals, and 13 assists in all competitions under his belt, he is still celebrated among the Arsenal staff for his humble approach and ferocious work ethic on the pitch and at the club's London Colney training ground.

'I love him, honestly, I love him,' assistant coach Steve Round told the latest instalment of the All or Nothing Arsenal docuseries, which will be streamed on Amazon Prime Video on Thursday. 'He just needs time, that's all.'

Round marvels at 'Gabi's' sharpness and speed.

'He's a great kid,' the coach told Edu, the club's technical director, as they sat in the canteen and watched Martinelli come in from training.

'He trains every day like it is his last day on earth. He is a diamond, he really is.'

Martinelli looked to be following a well-trodden path to the top as a young player at the prestigious academy of Corinthians, in Sao Paulo. But the forward left at the age of 14 and moved to the fourth-tier side, Ituano FC, just under 100 miles from his home in Guarulhos, a district of Sao Paulo.

The move allowed Martinelli to clock up experience in men's football, making his first-team debut at the age of 16.

'As a winger, as a wide forward, as a striker with freedom to roam, even as a No 10, an attacking midfielder, he did it all here,' Luiz Antonio, the youth manager at Ituano, told Breaking the Lines.

It is easy to see why Arsenal and coach Mikel Arteta like 'Gabi'. He is an excellent footballer, but they also describe him as a 'top' person, and that is given much weight at a club trying to regain its status among the elite.

'I grew up… in a poor neighbourhood with my parents,' Marinelli told the Prime Video cameras.

'When I was young, I didn't have money and they always say. 'don't spend a lot of money'. They are always 'on my foot'… 'be careful, be careful' [they say].

'But I don't care about the money,' he says shrugging. 'I just want to play football and my parents can take care of the money.

'It was quite tough, because in Brazil, I didn't learn English. And my family was so important for me. They always give me some good advice.

'If you want to be a top player, if you don't give everything today, you cannot improve. If you train [at 90 per cent] you cannot reach up, but if you train at 100 per cent, you can go to another level.

Martinelli's mum and dad came to the UK to help him settle in his new surroundings and still visit when they can. When they are not here, the player has fellow Brazilian, Edu, to keep an eye on him.

The pair were filmed by Amazon Prime Video speaking in Portuguese with Edu taking a touching, paternal interest in Martinelli and his family.

'As a person, he is a top boy,' says Edu, who explains the hunger of many young Brazilian players.

'The passion we have in Brazil is amazing,' he told Prime Video. 'How we live football in Brazil is something really, really special.

'[We say in Brazil] you go to the field, [players are] hungry, but they have just one plate to eat. Who is going to eat? Me or you? No, I'm going to eat.'

Even by Brazilian standards, Martinelli is hungry. Compatriot and new signing, Gabriel Jesus, has described him as an 'animal' for his work ethic and energy.

Signed from Ituano for £6M, with just 17 appearances and six goals to his name, the plan was to allow Martinelli time to develop in the club's academy with the Under 23s, but he made a huge impact on a pre-season tour to America and in training, so manager Unai Emery promoted him quickly to the first-team squad.

The young Brazilian scored his first two goals for the Gunners in a 5-0 drubbing of Nottingham Forest in the League Cup in September 2019.

Head coach Emery said: 'He's hungry to have that opportunity to help us, he is very humble, he fights. I told him to have some patience for his opportunity to do like he was doing. He did that. He deserved it'.

Martinelli signed a new contract in 2020, which runs until 2024 and it reportedly secures him almost £100,000 per week. It is likely to be reviewed again.

Three caps for Brazil and 36 appearances last season for Arsenal, 29 in the Premier League, bringing six goals, has widened the audience for his talents, making fans nervous that other clubs will seek to secure his services.

Liverpool's Jurgen Klopp is an admirer, labelling Martinelli as 'unbelievable' soon after his arrival in England. But for the time being, Martinelli does not look further than north London.

'Arsenal are a giant team. If I can, I'll stay here my whole life,' Martinelli told ESPN, earlier this year.

'I want to conquer things. I already said I want to stay here and win titles, with this wonderful crowd, my teammates. We have a young group, we have a lot of time ahead of us, players with a lot of quality, I think we will achieve great things.'

Martinelli is now well established in the Arsenal first team and his explosive performances and never-say-die attitude, not to mention his goals, makes him a fan favourite, too.

He is well placed to develop further this season. He embodies Arteta's values of respect, commitment and passion, and now he has a new role in helping recent signings settle in.

Martinelli has struck up a good relationship Portuguese Fabio Vieira, the £30million midfield signing from Porto, and he is likely to be a key figure for young Brazilian, Marquinhos, 19, too.

The South American forward signed from Sao Paulo this summer and like Martinelli, has been earmarked for the U23s, but may yet make a pitch for a first team place.

He has certainly impressed his new team mates in the same way.

'How Gabi adapted at this level was unbelievable,' said the senior pro in the Arsenal dressing room, Granit Xhaka, 29. 'And I have the same feeling with Marquinhos as well.'

At only 21, Martinelli can be the mentor for the new kids on the block, which can only speed his own development. Meanwhile, the arrival of Jesus at centre forward, to replace Pierre-Emerick Aubameyang, will give the determined winger a target to aim for when he has beaten his full back. It promises to be an exciting season at the Emirates.