There are few things more likely to damn an Argentinian player than playing in Argentina. Even before the latest economic turmoil there was no money in the game and that – the wisdom of the talent doughnut has it – means any Argentinian who found himself in the Primera was either under 20, over 30 or not very good. Facundo “Chucky” Ferreyra, who completed a loan deal to Newcastle United on Sunday, bypassing the need for a work-permit through his Italian heritage, did not leave till he was 22, which is indicative of the doubts that have always surrounded him.

For a while those doubts threatened to get the better of him. He had begun his career with Banfield, making his debut as a 17-year-old, but when they were relegated to the Primera B Nacional in 2012 he left for Veléz Sarsfield after reported interest from Newcastle, Porto and Juventus failed to turn into a move. At first, it seemed he was not quite sure he was ready even for the step up he had made. He wandered around wearing an attitude of vague anxiety. Was he disappointed not to have moved to Europe? Did he opt not to take up offers? And if so, was he wisely insisting on developing his game at home or was he showing a lack of ambition? It was never entirely clear.

He did not play in the first three games of the season. He was sent off after 24 minutes of his second appearance, having come on as a substitute against Belgrano. He did score twice against San Lorenzo, but after Veléz had played 12 matches of the Torneo Inicial, those were still his only goals. He panicked in front of goal, his detractors said; he wasn’t clinical enough. Fans were grumbling; pundits were becoming increasingly convinced that he was yet another Argentina youth international who was failing to develop – a problem that endures; the youngest player in the Argentina squad at the World Cup was Marcos Rojo at 24.

Yet Ferreyra has always had his apologists. The “Chucky” nickname, after the doll in the Child’s Play films, was bestowed early, supposedly because he used to terrify opposing defenders in youth games (although some say his grandparents gave him his nickname because he was so mischievous) and while he may not quite have been doing that at Veléz, his movement was clearly thoughtful. At the Under-20 World Cup in Colombia in 2011, he had looked at times a little ponderous, his finishing uncertain – he scored once in Argentina’s five matches there, and that in a routine 3-0 win over North Korea – but he had frequently dropped deep to create space for Erik Lamela to swoop into from the left flank. He was a forward, his fans said, who should not be measured so much by his goals as by how he manipulated opposing defences: the doll had become puppet master.

And then, in November 2012, came an away game at defending champions Arsenal de Sarandí. Veléz were third, the title a possibility. This seemed a key test. A minute in, the Arsenal goalkeeper Cristian Campestrini spilled a shot from Alejandro Cabral and Ferreyra knocked in the rebound. That was simple enough but his second was something special.

Watching Argentinian league games can at time feel like watching English matches from the late 1980s, urgency replacing quality (because most of the quality has decamped for Europe) but that Veléz were a side capable of controlled, technically adept football. They had strung together 18 passes when Lucas Pratto pulled the ball back from the goalline. Ferreyra had made the ideal near-post run, and then finished superbly, lifting the ball first-time over the dive of Campestrini. He then thumped in his hat-trick goal from the edge of the box after another flowing Veléz move. Veléz won 5-1 but it was an odd game: they had only five chances – no lack of clinical finishing there.

Ferreyra was suddenly unstoppable. He got both goals in a 2-1 win over Godoy Cruz the following week, the winner against Quilmes the week after that and, although he broke his streak in a defeat to Boca Juniors, he added a further five goals in the final three games of the season as Veléz took the title. Thirteen goals made him the league’s joint top-scorer – with Ignacio Scocco, who left Sunderland a fortnight ago after a disappointing six months.

An ankle injury restricted Ferreyra and he never really established himself at Shakhtar Donetsk – although he did get a hat-trick against the Ukrainian Arsenal, which opens the possibility of a unique hat-trick of hat-tricks when Newcastle go to the Emirates in December – and that means that even now there is no clear picture of his abilities.

He is likely to find holding up the ball rather harder than he did in Argentina. There must be a concern that the direct style Alan Pardew has favoured will not make best use of the intelligence of his movement but he is clearly a player of some potential. Equally obviously, he is a confidence player: the difference between those early games at Veléz and his form after the hat-trick was vast.

There is a possibility he will exist in the shadows as Scocco did at the Stadium of Light but if he gets on a streak, he has shown he can be devastating.