It's difficult to imagine a starker contrast between performance and outcome than England's 1-0 victory over Slovenia at Wembley on Thursday night.

The narrow win, sealed by Harry Kane's last-gasp goal, didn't really mask an uninspiring performance from manager Gareth Southgate's side. But ultimately it means England have qualified for next summer's World Cup. Preparation starts now: The FA immediately announced home friendlies against Germany and Brazil next month, knowing those dates wouldn't be needed for playoff matches, while Sunday's trip to Lithuania effectively has become another friendly, a chance for experimentation. And experimentation is crucial if England have any chance of reaching the latter stages in Russia next year.

International friendlies are hardly a typical source of excitement, but noncompetitive matches have produced the most intriguing moments of Southgate's leadership so far. Last November there was a 2-2 draw with Spain, when England were 2-0 up until the 89th minute. This year, England lost 1-0 at Germany in March, then 3-2 at France in June. The positive thing from those matches, however, was that Southgate deployed a 3-4-2-1 system, after sticking solidly to a four-man defence throughout qualification. This points the way for England to play over the next nine months.

While England traditionally has been considered a nation of the flat back four, in truth there's been plenty of experimentation with a back three over the years: Bobby Robson, Terry Venables and Glenn Hoddle all used the system with reasonable success. The system largely went out of favour for England; Steve McClaren's one-off use of it in a disastrous 2-0 defeat at Croatia in 2006 didn't help. But now, the likes of Antonio Conte, Mauricio Pochettino and Arsene Wenger are using it regularly at the club level. The three-man defence seems modern again, and most of England's key players are either accustomed to the system or appear well-suited to it.

Southgate's biggest trump card is that so many of his first-team stars play together at Tottenham, who are temporarily sharing England's stadium. You can't boil Spain's 2010 World Cup victory and Germany's 2014 triumph down to a single factor, but it's impossible to ignore the fact that both depended upon the core of a cohesive, intelligent club side (Barcelona and Bayern Munich, respectively). Tottenham aren't quite at that level, but their progress over the past two seasons has been remarkable, and their tactical cohesion remains extremely impressive. To create the tactical harmony of a club side, Southgate should stick closely to the Tottenham model, a 3-4-2-1.

It's a wonder Gareth Southgate, a centre-back well-suited to a three-man defence as a player, hasn't brought that look to his English squad. Ian Kington/AFP/Getty Images

Working from front to back, this would mean England captain Harry Kane of Tottenham continues to play up front, with his closest support from club teammate Dele Alli, playing as an inside-left. England can't call upon Spurs' chief playmaker Christian Eriksen, who instead plays for Denmark, but Adam Lallana is a respectable replacement. Generally England's best performer since establishing himself in the side, Lallana takes up intelligent positions, quickens the tempo and forms passing triangles in dangerous zones. Much as Eriksen does for Spurs, Lallana is England's key man because he offers something different, a creative quality lacking elsewhere.

The wing-backs pick themselves. While Kyle Walker has departed for Manchester City, it's unlikely he's forgotten how to play in this "Tottenham system," while Danny Rose has yet to appear this season because of injury but is a natural for the left-side position.

In the centre, Eric Dier plays a physical holding role for Spurs and has generally performed well for England. Jordan Henderson would be Dier's most obvious partner in England's weakest outfield position. Henderson has rarely performed well for the national side but plays a defensive-minded role in Jurgen Klopp's pressing Liverpool style. Henderson should be able to adapt to a Pochettino-style approach. The emerging Harry Winks, another Tottenham player, received his first international call-up this week and is another option if he enjoys a good 2017-18.

At centre-back, there are no Tottenham options aside from moving Dier deeper. But John Stones has played in a three-man defence under Pep Guardiola at Manchester City and is perfect for bringing the ball forward, while Gary Cahill captains league champions Chelsea from the left-centre role of a three. Chris Smalling and Phil Jones have played in a three-man defence for Manchester United, albeit occasionally, and should have few problems adjusting.

It's relatively difficult to find many players who don't suit the system. For all his requests to play centrally, Alex Oxlade-Chamberlain appears best at wing-back. Ryan Bertrand has the versatility to play on the left of a back three or as a wing-back, while Danny Welbeck has done well in Arsenal's 3-4-2-1.

Arguably the biggest loser would be Raheem Sterling, although he was fielded as a No. 10 on Thursday, suggesting Southgate would happily field him as an inside-forward too. Marcus Rashford, England's brightest player against Slovenia, would struggle to find a place, but ultimately he doesn't look entirely comfortable out wide and probably will be a backup to Kane regardless of the system.

In fact, the main question should be why Southgate, a cultured centre-back well-suited to the three-man defence in his playing days, hasn't been using the three-man defence all along. Drab displays in unconvincing wins over Malta, Slovakia and Slovenia have done little to restore faith in the England side, which means Southgate essentially has nothing to lose by changing his system.

The 3-4-2-1 is the system of the moment. It's the system of league champions Chelsea, FA Cup winners Arsenal and the side that contributes the most players to this England side. Southgate would be foolish not to switch to the formation that makes his players most comfortable, starting Sunday against Lithuania.