England defeated Australia by 3 wickets to make the series 1-2.
The Barmy Army, who have made the Walkabout their official headquarters for the week, were not happy with the news.
England declared at 393/8 after Root hit his first century against Australia after 2015.
The present quartet of top batsmen emerged almost two decades after the retirement of the four great all-rounders.
England have already named their starting 11, giving a Test debut to Liam Livingstone and recalling Ben Duckett to open with Zak Crawley.
South Africa secured a 62-run victory in sweltering heat in the first One-Day International.
Root went on to smash a masterly 142 not out, his 28th Test century, forging a mammoth 269-run partnership for the unbroken fourth wicket with Bairstow, who remained unbeaten on 114.
The victory was a tribute to England’s belief and their cavalier approach under the new captain-coach combination of Ben Stokes and Brendon McCullum.
"Joe just loves batting," said Matt. "As a kid, wherever someone would bowl at him he'd be there with a bat. He just loves doing it, he just loves batting."
The 31-year-old stepped down as skipper in the aftermath of England's 1-0 series defeat in the Caribbean in March, which came on the heels of a disastrous 4-0 loss against Australia in the Ashes.