Of the 4,000 men who currently play professional football in England, not one is openly gay. When you think about it, that’s a mind-boggling statistic. Within society at large, homosexuality is becoming ever more accepted. Yet scores of soccer players – hundreds, probably – lead lives founded upon positively 19th-century levels of concealment. Living as they must in constant fear of exposure, how do such men accommodate themselves to the sport’s bizarre behavioural codes – the hyper-masculine excesses that are themselves tinged with homo-eroticism? In the hotel room, in the nightclub, when the time comes for them to “perform”, how do they react, and what goes through their minds? Such questions are, for the most part, unanswerable.

Except, of course, to a writer as talented as Ross Raisin, whose first two novels (God’s Own Country and Waterline) hinted strongly at what he’s capable of. Now, in his supremely accomplished and moving new novel, Raisin imagines the life of a young footballer who, over the course of a couple of seasons, unhappily discovers that he’s attracted to “fellas”. When A Natural opens, Tom Pearman has just been signed by “Town”, a team newly promoted to League Two from the unfathomable depths of the (non-league) Conference. Already, at 19, Tom feels that his career is hanging in the balance: his move to Town, hundreds of miles away from his home in the north, was prompted by having been let go by the Premier League club whose ranks he’d progressed through as a junior. Will he ever make it back to the top flight? Having always believed that a glittering career awaited him – and having been told all his life he was “a natural” – Tom now finds himself agonisingly lacking in confidence.

This is, apart from anything else, a superb evocation of life in football’s lower echelons. With a calm meticulousness that never becomes tedious, Raisin sketches Tom’s first few weeks at the club, introducing us to his team-mates, the family he and two other young players lodge with, the “gaffer” who fits in his coaching duties around the demands of running a van-hire firm. Lacking the wealth and glamour of the Premier League (the captain – wait for it – is on two grand a week!), this is a side of the game that doesn’t often get written about; and yet, in Raisin’s handling, every detail is fascinating. The world he conjures up is by no means pleasant. What emerges most forcefully is the sheer brutality of a system that wrenches immature young men from their families and then coops them up together, away from real life, before, very often, unceremoniously returning them to it. For those who instinctively feel that all footballers are pampered brats, A Natural is a bracing corrective.

The theme of gayness creeps in slowly, emerging in step with Tom’s burgeoning interest in the head groundsman, a pasty, ginger-haired figure who himself played for the club as a junior before being kicked, as it were, into the long grass. Most of Tom’s team-mates are indifferent to Liam, but Tom finds his eyes constantly drawn to the placid figure on his tractor, or to the hut to which he regularly retires for cups of tea. Bit by bit, a rapport between the two develops, although at first Tom can’t give voice to his feelings. Raisin, who isn’t himself gay, writes with remarkable delicacy about the gradual build-up of passion, the move into something resembling a relationship, though one never untainted by shame and disgust. The restraint of the writing here feels necessary, truthful: it’s as if, in never giving direct voice to Tom’s desires, Raisin is linguistically inhabiting his denial.

Frequently, reading A Natural, I was reminded of another novel about a young person pitched into an alien world. In some ways, Colm Tóibín’s Brooklyn is the obverse of Raisin’s book: not a novel by a straight writer about a gay man, but a novel by a gay man that centres on a straight protagonist. (It tells the story of a young female émigré from Ireland to New York in the early 1960s.) Both novels are filtered through a similar consciousness: one that is naive, private, intensely passionate but also scared. Both are written in deceptively simple prose that belies their urgency, the richness of their understanding. A Natural may not quite reach the heights of Brooklyn – few novels do – but it’s still a masterful performance.

There are some flaws. A subplot that focuses on the domestic life of the two-grand-a-week captain is readable enough, but feels a little generic. Just occasionally, the plotting seems forced: for example, one crucial development near the end depends on an otherwise sympathetic young woman suddenly experiencing intensely homophobic feelings; to me, this didn’t quite ring true. But for the most part, there’s very little to fault.

Raisin even triumphs in areas he has no right to, such as in making us believe that he knows what playing professional football feels like. (Every cliche-wielding hack should read his descriptions of Town’s matches.) This is a gripping, mature, important novel. It would be a travesty if it doesn’t win prizes.

• A Natural by Ross Raisin is published by Jonathan Cape (£14.99). To order a copy for £11.24 go to bookshop.theguardian.com or call 0330 333 6846. Free UK p&p over £10, online orders only. Phone orders min p&p of £1.99