Here is the next big selection dilemma for Arsene Wenger: Jack Wilshere or Aaron Ramsey.
A few years ago, the answer would have been patently obvious to anyone who watched the team play. During the 2010-11 season, Wilshere emerged as one of the brightest young stars in football, dominating the Premier League and Champions League alongside Cesc Fabregas.
It seemed clear that he would be the best of the many young talents the Gunners were developing at the time. Wilshere had everything: the grit to play in defensive midfield and the technical ability to thrive further up the pitch; an archetypal box-to-box midfielder.
We know what happened next, of course. Wilshere injured his ankle playing in a friendly for England, not to be seen again on a football pitch for another 17 months.
That gave Aaron Ramsey his opportunity. It took the Welshman a while to find form after Wilshere's absence opened an opportune hole in Arsenal's midfield, but, with Wilshere unable to maintain his fitness for prolonged stretches he had ample time to simplify his game.
Suddenly, he became undroppable. At first his main asset was merely remarkable stamina and a work rate that allowed him to cover a remarkable amount of the field, but last season he added a clinical goalscoring touch that made him one of the best midfielders in the world.
In most cases, the emergence of two young stars would be a fantastic boon for a club. The problem, however, is that the two play the exact same position.
Both are box-to-box midfielders, but both are at their best in the central pivot position that Arsenal's system creates.
The setup is commonly this: a holding/defensive midfielder (usually Mikel Arteta), a true central midfielder (Ramsey or Wilshere), and a roving attacking midfielder (Mesut Ozil).
Ozil is too good to be displaced, and neither Ramsey nor Wilshere is sufficiently defensively minded to fill the spot at the foot of midfield by himself. Therein lies the selection dilemma.
At this point, Ramsey is unquestionably the victor in the battle for Arsene Wenger's favor. The Welshman was the linchpin of the team whenever he played last season and was often simply unstoppable.
Moreover, Wilshere might have had the opportunity to put a dent in Ramsey's dominance last season when Ramsey was injured for several months during the second half of last season. But he just could not maintain his fitness; Wilshere always seems to throw himself into challenges and get himself banjaxed.
All the relatively small periods for which he is usually out add up very quickly, and, importantly, prevent him from building fitness, form and confidence.
While it does not seem at first analysis that there is a way for Wilshere and Ramsey to coexist in the same midfield, a little tactical tinkering reveals a potentially fruitful arrangement.
Remove the single defensive midfielder and create a double-pivot with Ramsey and Wilshere at the back of midfield together. Let Ozil roam as he currently does as an attacking midfielder, and leave the rest of the team intact.
The result would look like a 4-2-3-1 formation, but could even become a 4-2-1-3, depending on where Ozil positions himself. This way, Ramsey and Wilshere would share the defensive burden, allowing one to maraud forward while the other stays back and guards the back line.
Disciplining both to control their attacking urges might be a problem, as will be the pocket of space that would be left between the double-pivot and Ozil. But, in theory, it could work.
However, this would leave Mikel Arteta high and dry, and prevent the defensive midfielder signing that so many hoped for this summer. In the short term, at least, it does not seem that Arsene Wenger has any plans to make this theoretical partnership a reality.
As long as the manager keeps his current system in place, there is no way for Ramsey and Wilshere to play in midfield together unless Mesut Ozil or Mikel Arteta is out.