The news this week that Cristiano Ronaldo, the world's most unwaveringly delighted man, is "unhappy" at Real Madrid was, at first, quite hard to digest. It is true that Ronaldo looked if not unhappy then at least magisterially affronted when Barcelona skill-pixie Andrés Iniesta was named European player of the year last week, but unhappiness still seems a considerable sideways leap. It is important to remember who we're dealing with here. Philip Larkin once argued convincingly that happiness, in the modern sense of "a continual emotional orgasm", doesn't really exist at all: the semi-permanent happiness of people in magazines or of handsome, flinty-eyed men in TV adverts lulled into a state of zen-like vegetative contentment simply by driving along a stretch of deserted A road in a high-spec Japanese saloon car. This kind of tangible, life-styled happiness, Larkin argued, has never truly existed and is in fact a basic human impossibility.

But then, Larkin never met Ronaldo, a man who from a distance appears entirely consumed with the business of being almost overwhelmingly pleased with things. A single, nonchalant flare of those rippling, mahogany neck muscles is enough to convey absolute, unshakeable contentment with a life spent either performing arm-waggling feats of playground-football genius or being ferried via fur-lined helicopter from manicurist to masseuse to groupie-thronged penthouse spa while reclining on a herb-encrusted chaise longue dressed in emu-skin bikini underpants and a solid gold top hat.

A non-happy, non-triumphant Ronaldo seems not just wrong but baffling. What, in that case, does he think is the point of him? It is a complete dereliction of his basic function. Even the tone and texture of Ronaldo's footballing greatness suggests an indissoluble self-pleasuring certainty. This is a player who each time he receives the ball turns and sprints with a singular abandon that seems to suggests he is being chased not just by the opposition but by everyone in the stadium – his own team, the referee, both benches – and it is all he can do to loose off a shot before the entire enflamed, third-rate, sub-Ronaldo world falls upon him in a jealous rage of flying fists and Chinese burns.

And yet Ronaldo's unhappiness gained an added thrust with the news later in the week that Cesc Fábregas is also unhappy. Whatever the collective term is for gaggle of unhappy La Liga superstars – an open letter of unhappy midfielders, a golfing exile of sullen, freelance goal entertainers – it seems we have an outbreak on our hands.

Fábregas has, he says, been "wearing his happy face", presumably as an additional layer over the top of his furious face after failing to play an entire 90 minutes this season.

This dual big-name sadness situation is made all the more surprising by the fact both players moved to their current clubs for reasons connected, above all, with personal happiness. For Ronaldo it was the Iberian lure of Madrid. This was a soul-searcher's transfer, albeit one that pales next to the tear-sodden brouhaha of Fábregas returning to Barcelona, presented as not so much a transfer as a harmonising of the spheres, the long walk to freedom, a very sad small lonely puppy finally scratching at the back door after eight long years of chasing the wrong station wagon down the freeway and spending its nights mewling at the stars.

If Ronaldo's unhappiness is only conceivable as a a very slight disturbance in the corner of his glazed and sealed perfecto-environment, Fábregas has always in truth had something of the needy ex-girlfriend about him. The sheer overwhelming schmaltz effect of that return to Barcelona always suggested it was likely to be a bit of a disappointment, like the kind of person who goes on about their impending wedding for months, even years, conjuring a sacred ecstasy of flowers and petal strewn first dance routines before, like everyone else who ever made the same commitment, spending a large part of the rest of your life arguing quietly in traffic jams. Of course, the assumption is this is not unhappiness in the way it is understood by the truly miserable, the disenfranchised, or the teenaged. Instead it is a familiar kind of semaphore, a political-economic declaration of future flounce-out capacity, like the Queen placing her handbag on the floor at dinner to indicate she wishes to leave. This is nowthe fashion among superstar players, public unhappiness a form of aggressive, internal marketing, a suggestion that they are already whirling and thrumming on the helipad, an inner ring of dependents and shiny-suited hangers-on scrambling for the lurching undercarriage.

In Ronaldo's case some kind of inexplicable pay-rise clog in the Madrid hierarchy has already been fingered as the unhappiness maker, a refusal to provide any advance on his current position as merely the 10th best-paid player in the world. Fábregas is a more complicated case. He is, let's face it, somehow shaping up as not quite as good as he should be, looking a bit like a Premier League-reared, own-brand version of the incumbent Barcelona real deal, an Aldi Iniesta, a Taste the Difference Xavi. At Arsenal things were so much simpler. He could at least appear elegantly exotic with his "passing" and his air of self-possession, an exiled prince, all promise and purpose. Whereas there seems to be an oppressive air of Barça-branded happiness about life at the Camp Nou, a high-visibility familial swank-about, like the rather wearing display-happiness of electioneering America politicians or people on competitive shared family holidays where behind the guffaws and back-slaps everybody secretly hates each other after the first day.

And perhaps in Fábregas's unhappiness there is even some comfort to be taken. It is above all the sense of distance, the disjunct between the captive princes of the elite and those who swoon remotely that seems perhaps the saddest thing about modern football. But unhappiness happens to everyone, even the rich and famous, and it would be a mistake to assume that footballers, as a species, have ever been immune from their own bespoke strain of misery. From the feudal conscription system of early football through to today's gilded Euro superstar imprisoned within the giant clamping headphones of celebrified alienation, perhaps we should stand up in solidarity for the footballer's right to be unhappy. The suspicion is, of course, that this kind of unhappiness may be eminently curable.

But while it lasts unhappy Ronaldo and sad Cesc seem not just watchable but oddly likeable too. I cherish their unhappiness.

Self-serving, trivial, a canker of compromise and trapped ambition it is, for now at least, all reassuringly familiar.