The secret to the most successful sports teams is that there's always something, or someone, they are working on. Their goal is to have a support cast that is as good as their starting XI, a depth that can drown out the opposition, and to do that they need to practice some form of player rotation.
We see it in cricket often. All-format players have their workloads managed in less-than-crucial clashes. Fast bowlers are rested, some batsmen make way for others and occasionally a struggling player is given a break (read: dropped) to allow them to get away from their troubles. That's what happened to Stephen Cook, whose struggles on a second away tour this summer saw him sidelined for the Hamilton Test.
In principle, it's not the worst idea. Imagine if you were going through a tough time at work and your boss told you to take a week off and serve your colleagues tea instead? You may not like the waitering part but at least you wouldn't have to think about unhappy clients or poor customer feedback or whatever it was that caused you to become bad (or just not good) at your job.
In theory, it would only work if there was someone else who could do your job at least as well as you during your sabbatical. Your bosses would prefer it if they did it better; you, of course, would not. And in sport, are no such guarantees.
When JP Duminy came in for an injured Ashwell Prince in Australia in 2008-09, he helped South Africa to a first series win down under and Prince had to fight his way back. Those kinds of things happen. It may still happen to Cook here and if it does, fair play to Theunis de Bruyn. But it still raises the question of whether this was the best course of action both for de Bruyn, who was asked to play out of position, and Cook, who spent seven seasons banging down the door for a place in the national team.
History could give us the first clues. This is not the first time South Africa have done this in the recent past. Stiaan van Zyl sat out the final Test in India after scores of 5, 36, 10, 0 and 5. He was dismissed by R Ashwin all five times and his technique looked as scrambled as his mind.
Cook's situation is not nearly as dire. Although his numbers in New Zealand are worse - 3, 11, 3, 0 - his overall record is better than van Zyl's at a similar stage. Van Zyl, a regular No.3 or lower, had not scored more than 34 batting in the top two, when he was given a game off; Cook, a regular opener, already has three centuries to his name. Although scratchy at the crease, which is actually how he always plays, Cook does not look nearly as down as van Zyl did, and even if he is feeling a little unsure, this would have been the ideal opportunity to bulk up. He has fallen to Trent Boult and Tim Southee twice each in this series and, neither are playing in this match. Colin de Grandhomme, who has bowled with subtle danger, may have asked questions but Cook should have been given the chance to see if he could answer them and not time off.
It is the least that could have been afforded to a man who is set to play in England later this year. Cook would not have been awarded his first national contract if that was not the case and he probably would not have signed an overseas deal with Durham for the first half the county season if it was not the case In fact, he might have gone Kolpak if he didn't think he had some sort of international future but that is another discussion.
Given how Cook performed under pressure in Adelaide last year - when he followed a lean two Tests in Australia with a century - the last thing he would have wanted was to be prevented from seeing if he could do the same here. Although Hashim Amla explained a "mature," Cook would have taken the news well, he also suggested any out-of-form player would have preferred game time, "You want to keep playing," Amla said. "You believe the runs will come and playing is the only way the runs will come."
Then there is the question of Theunis de Bruyn. At 24, he still has a long time to carve out an international career and this may be nothing more than a false start but it probably hasn't sent out the best message. When van Zyl was dropped, Bavuma was the reserve batsman on the tour and he was asked to open, having already played four Tests in the middle-order. Bavuma knew he wasn't an experiment, just some emergency relief. De Bruyn may not be so sure.
South Africa have history with manufacturing openers (van Zyl is a case in point), especially when there are no other spots for them and he could see this as his only "in," to a packed batting line-up even if it shouldn't be. De Bruyn is a No.3 batsman and a middle-order place would be a better place to start especially since South Africa have problems there too.
Duminy is also in a drought and actually seems to want a break. He has opted out of the IPL in order to mentally refresh for South Africa's three-month tour of England. Why not allow that process to begin a week earlier?
There are considerations like Duminy's seniority and the transformation targets (six players of colour, two black African calculated on average over a season) but the former may actually be a reason to give him the time he needs and South Africa are well ahead of the latter.
If the selectors felt compelled to give de Bruyn a game that would have been the way to do it. But why might they have felt that way? Well, there is a recent example of a snubbed reserve batsman going rouge. Rilee Rossouw was the spare part in Australia and was said to be so unhappy with non-selection that when Cook was batting he decided to put pen to paper on his Kolpak deal. But the difference is that de Bruyn without a Test cap isn't eligible to do the same; de Bruyn with one is.
South Africa's selectors have barely put a foot wrong all season and have made many inspired choices, which have seen the emergence of players like Andile Phehluwayo, Lungi Ngidi and Dwaine Pretorius, but this may be their first mistake. Might they have dented the confidence of a man they will need in the next few months? Could they have opened the door for a promising young player to leave when he realises he may have to wait a while for another taste of international cricket? Or are they making a decision to go back to looking for the country's best batsman and turning him into an opener rather than looking for the best opener?