Arsenal's transfer business this summer could signal a return to the 4-4-2 formation. Manager Arsene Wenger is targeting players with the physical attributes and fluidity to finally make his preferred system work again.
Since around 2008, Wenger has relied on tactical structures that attempted to mask Arsenal's lack of imposing strength in midfield. He also utilised versions of the 4-3-3 and 4-2-3-1 as a means of accommodating squads overloaded with central playmakers.
But since Cesc Fabregas, the player most responsible for the tactical shift, left in 2011, Wenger has been re-shaping Arsenal to look like his squads of previous years.
Those efforts gathered pace when Wenger paid £42.5 million for Mesut Ozil last summer. The World Cup-winning Germany schemer can operate on the flanks or behind a striker. He's played both roles since joining the Gunners.
But it's this summer's business that offers the biggest key to reviving the 4-4-2. Specifically, it's Wenger's reported pursuit of German midfield powerhouses Sami Khedira and Lars Bender.
There are conflicting reports about Arsenal's chances of landing Khedira. However, Jeremy Wilson of The Daily Telegraph states Wenger has certainly made inquiries about the Real Madrid man, as well as Bender.
Interest in the pair shows Wenger is serious about making his team physically stronger in the middle. But he's also targeting greater energy. Both Bender and Khedira are tireless and powerful runners.
That's also an apt description of Arsenal's current talisman in midfield, Aaron Ramsey. Partnering Ramsey with Khedira or Bender would give Wenger the power in the middle to support playing two strikers.
One of those strikers could be new boy Alexis Sanchez. He didn't always thrive for Barcelona when forced out onto the right wing. However, Sanchez did flourish in a two-pronged strike force for Chile at the 2014 FIFA World Cup, alongside Eduardo Vargas.
Wenger recently described Sanchez as a "modern striker," in an interview with Eurosport. In the same interview Wenger endorsed the player's versatility, specifically his ability to operate "through the middle."
Sanchez may not be many people's idea of a classic striker. But neither was Thierry Henry when Wenger brought him off the wing and made him a star.
Fluid movement was the key to Henry's game and what made Arsenal tick. Things will work the same way with Sanchez.
Wenger also needs a powerful base in the middle to support fluidity from the flanks. Specifically, he needs willing runners to cover the roaming tendencies of playmakers Santi Cazorla and Ozil.
That duo could easily start games wide in a four-man midfield. Neither would be confined to those positions.
Wenger has always favoured inverted wingers. Marc Overmars was more supporting striker than natural wide man. Robert Pires was a true false 11, a player who routinely drifted off the left and into central areas.
Cazorla played a similar role under Manchester City boss Manuel Pellegrini for La Liga teams Villarreal and Malaga. He has enjoyed the same freedom since moving to Arsenal in 2012.
Ozil is also defined by his nomadic inclinations on the pitch. No matter where he begins a match, Ozil causes damage from multiple positions.
But a team that lets its wide players roam needs two elements to help compensate for the breakdown in structure. The first is energetic central players willing to tuck into the vacated spaces if needed.
Ramsey certainly does that. The Wales ace has a fine understanding of the game and a natural instinct for where he's needed.
His experience operating at multiple positions for Arsenal has ensured that. Khedira and Bender possess those same qualities.
Ozil knows Khedira will cover the spaces he vacates when the two play for Germany. That leaves Ozil free to concentrate on his creative output:
Bender may be a little more defensive-minded than Khedira. Yet that would certainly be no bad thing in this type of midfield.
The second thing a four-man midfield with inverted wingers needs is overlapping full-backs to provide genuine width. Arsenal have lost Bacary Sagna but proposed replacement Mathieu Debuchy can certainly raid the right flank.
Website 101 Great Goals expects Debuchy to join Arsenal in the next 48 hours, after the Magpies signed a replacement in the form of Dutchman Daryl Janmaat:
Debuchy can provide width on the right. The same is true of either Kieran Gibbs or Nacho Monreal over on the left.
The 4-4-2 described here compares favourably to how Wenger used to deploy his team. Let's consider the unbeaten squad of 2003/04 as the template.
That group was really 4-4-2 in name only. Both Pires and Freddie Ljungberg regularly drifted off the wings. Pires wandered into the middle to give Arsenal three central players.
Ljungberg's movement was more direct to target gaps through the middle of a back four. His runs often made him a supporting striker.
Width was still provided by the natural raids of full-backs Ashley Cole and Lauren. Centrally, Patrick Vieira and Gilberto Silva both shared defensive responsibilities and pushed on when they could. The pair rotated their positions responsibly and played with intelligence.
Further forward, Henry was the key to everything. His habit of frequently drifting over to the left flank opened up space for forward breaks from Pires and Vieira.
When Pires broke, natural No. 10 Dennis Bergkamp would often drop into the middle. He would be perfectly positioned to thread passes through to runners like Vieira, Pires or Ljungberg.
Alternatively, with defenders drawn to those runs, Bergkamp could simply lift a pass over the top for Henry to sprint onto from the left.
Those are merely crude examples of how things worked. The point of it all was the movement. Players constantly rotated positions. Yet they did so from a sound base and structure.
That solidity is best offered by the naturally favourable dynamics of the 4-4-2. It's why Wenger has always loved the formation.
Now consider this season's potential team. Width is assured if Gibbs and Debuchy are the full-backs.
Ozil and Cazorla could operate either side of a middle four in front of them. They would bracket Ramsey and either Khedira or Bender. Both schemers would have full licence to roam, while Ramsey and his midfield partner fill in and take turns breaking forward.
Up front, Sanchez would have the key role. He could drop off into a No. 10 position when Arsenal don't have the ball. That would create five in midfield and also position Sanchez perfectly for a counter attack.
He could also drift out of the middle to the wings, timing his movement to match a run into the middle from either Cazorla or Ozil. Sanchez could work with Olivier Giroud, who would remain a natural focal point around which all of the runners would move and play.
Alternatively, Wenger could partner Sanchez and Theo Walcott through the middle. That would encourage even greater fluidity.
Sanchez would be the vital man in this new-look alignment. All of the midfield would make their runs reacting to his movement.
In this sense, Arsenal's 4-4-2 structure would be loose and able to adopt different guises. That's just how things worked when the Gunners played the best football in the Premier League.
Wenger got a glimpse of how the 4-4-2 can still work today when he used it to salvage the FA Cup semi-final and final. Now he is recruiting personnel who can again make it Arsenal's formation of choice on a regular basis.