The diversity of England’s young squad has been a major factor for those of us who’ve been a bit iffy in the past about supporting the national team but are now getting behind Gareth Southgate’s boys. His side look just like a bunch of lads playing in your local park on a Sunday – only they’re better they’re better at kicking the ball. But do they represent modern England? Up to a point. The elephant in the room, in terms of diversity, is sexuality. This unassuming movie from Switzerland convincingly dramatises why a gay man in top flight football may choose stay in the closet. (There’s not an openly gay player in the 20 clubs of the Premier League.)

Max Hubacher gives a low-key, lived-in performance as hardworking Mario, the top scorer in a leading club’s under-21s team. Mario has been too focused on football to process the fact that he’s gay, but in the tense make-or-break season before he turns professional he falls in love with a teammate, flashy striker Leon (Aaron Altaras). Rumours are soon flying around the club about the couple.

The research here is scrupulous: the realistic-looking training sessions were shot at the grounds of FC Bern. The club’s response to the rumours has a ring of truth, too. Summoned to a meeting with the manager and chairman, Mario’s terrified he’ll be sacked. His agent shrewdly points out that the club has invested too much in him.

Mario is not football’s Brokeback Mountain. Writer and co-director Marcel Gisler is more interested in Mario’s real-world dilemma than in telling an epic love story. Should he come out and risk his career? How else will homophobia in football be tackled? Or keep his head down and get on with the job? He can always come out after retiring. At two hours, the film feels a little long, but this is a heartfelt and human drama with the texture of truth and characters to care about. The 18 certificate feels a bit harsh, though.