Although it has been rarely rolled out of late, and in spite of what Southgate says, the three-man backline is associated with some of England’s best times under the current manager.
There was the heady run to the semi-finals in 2018, while a back three was also deployed twice at Euro 2020.
England used it for the 2-0 last-16 victory over Germany, and the final versus Italy where they took an early lead before eventually succumbing on penalties.
Using it against Switzerland would mean Southgate reverting to what has worked before, while also looking for it to spark an improvement in England’s Euro 2024 performance.
They laboured against Slovakia, being open at the back while creating little in attack. Their first shot on target was Jude Bellingham’s overhead bolt from the blue in the fifth minute of second-half stoppage time.
Following dour draws with Denmark and Slovenia, the patience of Southgate – which ran longer than most pundits and supporters – has perhaps finally worn thin.
Southgate’s hand has also been forced by the personnel available to him.
Centre-back Marc Guehi, who had started every game to this point and impressed, is suspended having picked up two bookings.
The Crystal Palace player was rushed in as a defensive partner for John Stones after Harry Maguire was ruled out of the tournament by injury.
It is widely expected that Kyle Walker will slot in as a right-sided centre-back, a position he has regularly played for England when a back three has been used. Stones will take up the centre, while Southgate has three obvious options on the left side – Joe Gomez, Ezri Konsa or Lewis Dunk.
Another personnel issue is the ongoing left-back question.
Luke Shaw, England’s only specialist in that position, is back in training after injury but has not yet played in Germany following Southgate’s big gamble on his fitness.