There is a moment in Graeme Swann's video diaries of the last Ashes tour shot on Christmas Day, at the table reserved for the singletons, where he cries out: "Tell us a joke, Monty!" Sheepishly, Panesar mumbles that he does not know any, whereupon Swann mimics blowing his head off in despair at the company he is in. It might have been a harmless piece of badinage by the England team's most jocular character but it expresses the contrast between their leading tweakers: Swann the life and soul of any gathering, Panesar often painfully insular.
Yet the "trauma" to which Cook refers has of late taken a more sinister turn. Sources close to Panesar suggest he was deeply depressed in the aftermath of the split from his wife, Gursharan Rattan, a pharmacist, and that his series of bizarre misdemeanours have arisen as a consequence of his personal anguish. First there was the infamous night at Brighton's Shooshh club with his Sussex team-mates, where video footage shows him screaming "Help me!" as he is dragged along by the outraged security men.
Then, the demons spilt on to the pitch as Panesar received a one-match ban for intimidation, after he appeared to aim a kick at Worcestershire's Ross Whiteley as the batsman ran past him.
Cook does not dilute his words. "He seems to have become petulant," he says. "Some of his behaviour has been appalling."
The paradox is that such episodes sit so starkly at odds with the earlier impressions of Panesar's personality. Growing up in a Punjabi-speaking family in Stopsley, a suburb of Luton, he was inculcated by his father Paramjit, a carpenter, with the virtue of politeness.
John Williets, his sports master, recalls: "Mudhsuden was always quiet and conscientious, with excellent manners. Even when he visited the school again recently, he insisted on calling me 'Sir'. He was a lovely kid, from an intensely hard-working family."
Williets was abroad when the lurid tale of Panesar's Brighton disgrace broke and confesses to bafflement.
As a No11 batsman, Panesar was memorably labelled by Mike Atherton as a "rabbit of Watership Down proportions" and taunts from Australians unimpressed by the lack of variety in his play have stuck.
Cook says: "I'm inclined to agree with Shane Warne, who observed: 'Monty hasn't played 33 tests - he has played one test 33 times.' I haven't seen Monty evolve like I would have expected. I know the attributes I saw when he was 17 or 18, but he still looks to be exactly the same player."
The reality on this tour, given the primacy of Swann and the team's reluctance to field two spinners in any test, is that he will struggle for a look-in. But after Panesar's annus horribilis, it could be a chance for him to find his natural equilibrium.