If the Indian captain had gone down with Covid a week before a Test last summer in England, imagine the calamity. He didn't, but an outbreak among the support staff caused enough panic for the BCCI to have the Test called off.
A lot of it was to do with where the world was with the pandemic. The UK was leading a new, post-vaccine laissez-faire response by easing restrictions throughout society, but sport hadn't caught up. Players were still in bubbles; they underwent regular PCR tests; close contacts were still being identified and told to isolate; travel was a nightmare.
But some of it would also have been because the captain last summer was Virat Kohli. And such is the frenzy that accompanies Kohli, it's quite possible that if only he had gotten Covid and no one else, the Old Trafford Test might have been cancelled anyway.
It's a measure of how much has changed that Rohit Sharma got Covid this week and there's no question of the Test being in danger: the only question is who replaces him, if he doesn't recover in time. We've just seen the end of a series where a number of New Zealand players or staff got Covid, the England wicketkeeper got it during a Test and nobody really cared. Last summer was a different world, though it also doesn't feel that long ago; one side effect of Covid, regardless of whether you've had it or not, is a distorted sense of time.
Also, this is Rohit. Great batter, fine captain but not that stratosphere. He doesn't hold the fate of entire ecosystems in his hands. He does not appear on Forbes rich lists. He is not hanging with the LeBrons, the CR7s or the Messis on a global sporting icon list. In fact, one of the most interesting things about Rohit's appointment is that for the first time in well over a decade, an Indian captain is not obviously the biggest, most significant figure in the sport.
No team is really built in the image of one man alone, but that this was in some way, until very recently, Kohli's India is difficult to argue against. Now? There is a new coach to consider as well, a man who, albeit in a diametrically opposite way to Ravi Shastri, brings serious presence.
Ordinarily, this would all be considered serious change. And it is, except it doesn't come across that way. If Shastri brought the yang to Kohli's yang then, instinctively, Rahul Dravid brings the yin to Rohit's yin: two men attuned to the details and not just a big picture. Shastri, meanwhile, will end the series as a blustering, cheerleading commentator, having begun it as a blustering, cheerleading coach.
India don't do crisis or panic, now they merely move along unperturbed. KL Rahul, second-highest run-scorer in the series, is not here. No problem, here is Mayank Agarwal, who Rahul had replaced in the first place as opener at the start of this series last year after Agarwal sustained a concussion.
Many countries might bungle transitions involving their second-most prolific Test fast bowler ever, when he is still only 33. Ishant Sharma might have played his last Test and nobody appears overly concerned, or sentimental. Why would they when Mohammed Siraj is already so well established? Or when next man in could be Prasidh Krishna: tall and gangly like Ishant but quicker and bouncier, averaging less than 17 in ODIs and less than 18 in first-class cricket? R Ashwin is arguably India's greatest spinner but will probably not play this series. And India won't lose it. Ashwin not playing would simply underline how little has changed for India. With Rohit leading (assuming he plays), India could field as many as eight from the XI that took the series lead at The Oval.
But this Test isn't really about India, which itself is an unusual position for India to be in. This is about England. Usually, England are just some shade of England: a great orthodox batter, a charismatic allrounder, a couple of grand old seamers and seven others. They win at home, but never dominate. They don't win that much abroad. There is always angst, about some player, about techniques, about county cricket, about the health of Tests. Boring is not the right word for it. Familiar, oddly comforting, reassuringly there, might be.
The best thing about this Test is that this is not usual England. This is not another shade, it's already half a painting. England too have a different captain and coach since the last Test of this series. They will only play four from the XI that played at The Oval. That says that a lot has changed but it doesn't even begin to capture a fraction of it - or the speed at which it has happened.
Less than a month ago they were still that England. Now they are this England and even if we can get our heads around the Covid time warp, we might struggle to explain that three months ago, seven of this England side scored 324 runs across two innings in 154 overs. In doing so, they lost by 10 wickets.
If they were simply waiting to be told that this is a way to play the game, then it's a nice reminder that words retain power, that they are consequential, especially when coming from Brendon McCullum. But without Ben Stokes' actions, they might still have meant a lot less. Stokes has been good as captain - a revelation, even, particularly with his handling of Jack Leach - but his two dismissals in Trent Bridge and Headingley now appear as the precise moments of revelation, when The Word became The Deed.
It can easily be argued they were reckless dismissals: England were still 148 behind in Trent Bridge when he fell and he left them 55 for 5 at Headingley. They probably were. But they also epitomised precisely what, presumably, he and McCullum had been instructing England to do. Run into the fear, not away from it. And if the captain was doing it, there was no excuse for others not to.
The most vivid illustration of this emboldened mood is Jonny Bairstow. Last summer, at The Oval, as he was bowled - a calling card that dismissal - by Jasprit Bumrah for a four-ball duck, it was possible to ask where his Test career was going. He was in his ninth year as a Test cricketer, with decent periods but he was averaging 23 in the three years until the end of that Test. Shunted around through the middle order in that time, half his Tests as wicketkeeper-batter, half as batter, he wasn't this, he wasn't that, so what was he?
Batting is a feeling, Kumar Sangakkara said during a recent Sky Masterclass, inadvertently landing upon the truth of Bairstow in this last month. Bairstow already had two Test hundreds this year but his last three innings (369 runs, twice out, 293 balls, 46 fours and ten sixes) means even he might struggle to remember those two.
He has best understood batting as a feeling, not chained by strictures of technique or batting order or situation or even format. "Sometimes your own thoughts sabotage your ability to see the ball," McCullum said once, years ago, articulating a purity of state athletes strive for, only knowing that the more they strive, the further away it gets and that it is attained generally by accident, not design. Rarely can Bairstow's place in the Test side have made more sense.
Jonny solved, not even county cricket seems such an intractable problem. All it needs, it turns out, is for county cricketers to start playing like England's Test cricketers. Not the scheduling, or the pitches, or the number of counties, or the quality of the ball: just a sprinkle of this ethos from up above. Trickle-down economics has never made this much sense (to be fair, it did happen with Eoin Morgan's white-ball revolution, but that is a different beast).
India will recognise some of this giddiness. They are much further down the arc of this seismic change. Typically, they traversed it in a more considered way, but it was no less radical. Kohli did change the way India approached games, and those fundamentals are firmly established by now. They bat as we have known Test batting this century (rather than this last month). Cheteshwar Pujara is not going to reverse scoop anyone, though Rishabh Pant is a born Baz-baller.
Their eureka moment happened to their bowling - and hasn't stopped happening (Hi Umran Malik); in having a battery of strong, quick and durable bowlers; in being more capable of attack than ever before; in picking five of them. That will be the half of this contest with all the sexy in it: England's batting against India's bowling (and I don't think England will let Ravindra Jadeja bowl 30-11-50-2 like he did last time).
There's probably something to be said about the contrast in coaches though nothing beyond the superficial. Suffice to say, Dravid is fully aware of the sudden, whirlwind impact of Baz-ball: he was the captain caught in the headlights all those years ago of McCullum's era-defining 158 in the IPL opener.
There is probably also a little lament to be made: last year's series never got the end that it deserved. And this Test won't get the series it deserves.