"James McClean is bad," he wrote. The responses he received suggested that his view is shared.
Just over a year after he burst on to the scene, the Derry man is finding out about the cycle of the hype machine. In a short space of time, the next big thing can become the whipping boy.
Sunderland fans are now divided on a player who they took to their hearts last season.
Today, he will encounter the Premier League champions Manchester City who he terrorised in a 3-3 draw at Eastlands last March at a time when it seemed as though the League of Ireland graduate was capable of anything.
A month earlier, he had started his international career as a hero, welcomed on to the pitch with a reception that wouldn't have been out of a place at the end of a rock concert. Giovanni Trapattoni later wondered if the fans believed they were about to see Messi or Pele.
In a polite way, he was revealing his scepticism about the traction behind the McClean campaign, and his sparing use of the Creggan man in the Euros provided absolute proof of his reservations, although the 73-yearold seemed unsure about the credentials of any young players during that unfortunate experience.
Still, the consistent message from wise heads in the game was that McClean would find it hard to replicate his brilliant first album.
"I don't believe in second-season syndrome," he said in August, but soon afterwards Martin O'Neill acknowledged that the youngster was suffering from that familiar affliction. The Northern Irish boss' stock at Sunderland has almost moved in tandem with McClean's form graph.
Fittingly enough, it was an early strike from McClean that set the tone for the win over Reading earlier this month. When he is performing well, he is capable of making the Black Cats tick.
His critics point out that he is quite one-footed, even though he can be deployed on either the left or right flank. Therefore, defenders know which way he is going to go, and merely show him on to his right foot and restrict his impact.
Indeed, Trapattoni saw fit to start the 23-year-old in the centre of the park in the August friendly in Serbia.
The experiment ultimately proved unsuccessful, but he had shown enough on the training ground to be trusted in that berth.
And that is why those who know McClean well are at pains to stress that people just need to be patient during this blip rather than over-reacting.
"You have to remember that he's still fairly young and it's just over a year since he's been away from home," says Derry City chairman Philip O'Doherty, who keeps in touch with the growing list of players that the club have produced for cross-channel suitors in recent years.
"We're very proud with how he's established himself. He still plays in almost every game and there's still a lot of improvement to come with the fulltime training. At the same time, James will have to learn to cope with the challenge he faces now, but there are professional people at Sunderland and they'll bring him along." In certain quarters, there is a lack of sympathy for McClean because of aspects of his behaviour, invariably revolving around social media excesses.
A few ill-judged comments on Twitter have revealed a naive side to a character who had the common sense to realise at an early age that a teetotal approach to life gave him the best shot at realising his dream.
The baiting of spurned Northern Ireland fans was ill-advised, albeit paling in comparison to his performance at a press event last May where he claimed that Catholics don't feel comfortable playing at Windsor Park. That led to his representatives at Platinum One becoming very careful about granting future interview requests.
They couldn't prevent him brewing up a storm on the tweet machine, however, and his outburst in the wake of his non-appearance in September's win in Kazakhstan caused a world of problems.
For McClean, the biggest problem was the furious reaction of senior professionals who had previously championed his cause. The dressing-room will generally protect players through any controversy, but breaking an unwritten code by showing disrespect for those selected in preference is a serious no-no.
The subsequent furore about his decision to wear a jersey without a poppy said more about those who had a serious issue with it.
McClean's bottom-line loyalty is to his locality and, while others might have gone with the flow to avoid hassle, he stood firm by his beliefs, which is hardly a bad thing.
Nevertheless, the boos that followed from a section of Sunderland fans came from a frustration at his travails on the pitch. O'Neill feels his below-par performances are in part a confidence issue, while his agents organised for his pal, Eugene Ferry, to quit his role as assistant 'keeper at Derry City and relocate to Sunderland to provide support to a friend who still suffers from homesickness.
McClean recently admitted that his morale was damaged by his Polish experience, his first taste of rejection in a period where he was the man in demand.
We will learn a lot about his mettle in 2013. Certainly, the momentum generated by his emergence lost perspective, but it would be rash to make dramatic pronouncements about his current difficulties.
He is not Messi or Pele, but at times this season he hasn't looked like James McClean either.
Sunderland and Ireland could do with getting him back.