Even for Strachan's most supportive admirers – and the general enthusiasm towards him encompasses most Scotland fans and even many of his former sparring partners in the media – it has been impossible to shake off a nagging concern about what happened during his 51 miserable weeks on Teesside. Middlesbrough amount to only a fraction of Strachan's career but, for now, it remains relevant because it was his most recent managerial work and ended with supporters baying for him to be sacked.
The issue is this: do Scotland fans have reason to worry about Middlesbrough, or are the circumstances of time and place so different that what went wrong for him then is irrelevant now?
Strachan has been frank about his culpability for things going haywire at Boro. He has confessed to the mistake of trying to impose a system on a squad of players, rather than patiently assessing what they were capable of and then adopting a style and formation which maximised their strengths. It is odd that such a surprising and basic misjudgment could have been made by an intelligent, experienced and successful manager.
Naturally there was more to his Middlesbrough reign than that. Essentially, he took one look at the team he inherited from Gareth Southgate, didn't fancy it much, and tried to change the whole thing as quickly as he could. Including a handful of loans, he brought in 18 players in just under a year. Middlesbrough had been pretty under Southgate. They were pleasing on the eye, adventurous, young and willing to take chances.
They were fourth in the Championship when Strachan arrived. But they were also unreliable, naive, and not the best at looking after themselves when the going got tough. Strachan didn't see enough "men".
He has always had a thing for a team being built around a spine of strong players who can handle themselves mentally and physically. He tried to change the physique and the philosophy at Middlesbrough as quickly as he could and did it with a few players who had been hardened by the Old Firm furnace: Scott McDonald, Kris Boyd, Stephen McManus, Kevin Thomson, Barry Robson, Willo Flood and Chris Killen. Throw in Lee Miller, Merouane Zemmama and Andy Halliday and most of his signings were from Scottish football. He wanted athleticism and character. The idea of his team being soft appalled him.
Injuries and selling Adam Johnson for £7m didn't help but Strachan has acknowledged the failure was his. The gamble was that Middlesbrough would spend heavily to get straight back to the Barclays Premier League. Instead too many of the signings underperformed (for which, of course, he must share responsibility).
When he left they had sunk to 20th after just 13 wins in 46 matches, and were saddled with a much higher wage bill. Strachan famously felt so bad about his contribution that he waived his compensation. Does any of this matter to Scotland? Hopefully the situation is now so different as to minimise the significance.
The composition of his first squad for Wednesday's friendly against Estonia showed Strachan did not see the need for the root-and-branch change that he performed immediately at the Riverside and which led to such quick decline.
This time he stuck with what he inherited. Every one of the 28 men he selected has played for Scotland before. Among them they have 438 previous international appearances. If Darren Fletcher and Craig Gordon had been available that would have been another 101 caps' worth of experience. Scott Brown, Allan McGregor, Phil Bardsley, Gary Caldwell, James Morrison, Steven Naismith and Kris Commons are exactly the sort of players – and men – Strachan might have wished to have at Middlesbrough. He seems to be immediately content with the resources at his disposal for Scotland, which is far more than could be said of his last job. Generally, Strachan is at his best – and gets the most out of his teams – when he has experienced, proven players he respects and can trust.
He hasn't given much away about his likely tactics against Estonia and the subsequent World Cup qualifiers other than to say a shape will be found to accommodate all of those he regards as key players. There has been a strong hint, too, that a place will be made for Jordan Rhodes, presumably alongside Steven Fletcher.
Strachan predicted some withdrawals given the timing of this friendly, the unattractive circumstances of the fixture and the need to build an I'll-scratch-your-back-if-you-scratch-mine relationship with the club managers. But Craig Levein got a high attendance rate out of his players and Strachan must generate a mood that maintains it.
His time at Middlesbrough began poorly, with defeats against Plymouth and Crystal Palace, and never recovered. If he likes the look of this Scotland squad far more he can use it to make a good first impression of his own.