It was a surprise to most supporters to see Takehiro Tomiyasu lining up on the left flank against Leeds United.
When the line-up was announced, most supporters believed that it would be Cedric Soares moving over to the left-hand side.
It became clear that Mikel Arteta had analysed who in the Leeds United team would offer the greatest amount of threat to Arsenal.
The Brazilian Raphinha has already been linked with clubs such as Barcelona and PSG who will wait to pounce on the winger should Leeds go down.
Cedric was given the task with Rob Holding to deal with Jack Harrison.
He rarely allowed him space of time to cut inside and work his magic, with the Leeds winger subbed on the hour mark.
Gabriel Martinelli also successfully supported his wide partner.
Something that he had been criticised for when paired with Kieran Tierney in the past.
Although with the next match against Tottenham, it is highly likely that Tomiyasu will return to his more natural right-back role.
The reason for the switch is due to the presence of Antonio Conte’s most dangerous Spurs weapon.
Son Heung-min has had another unbelievably good season.
So good it is painful to write the words as I ponder how none of the European elite have tried to pry him away.
Playing on Spurs‘ left, it makes sense that Arteta would switch Tomiyasu back to the right flank to try and curb the South Korean’s effectiveness on the game.
He managed to do so brilliantly in the home match against Tottenham in the first half of the campaign.
It was probably Son’s worst game of the season, entirely due to Tomiyasu’s handling of the player.
The worry will exist though that an unorthodox Cedric will struggle to cope with Dejan Kulusevski.
Arguably Arteta could bring Nuno Tavares, a more comfortable left-footed player, back in at left-back.
That said, the youngster has also looked vulnerable defensively.
Arteta has a huge decision to make and cannot afford to get it wrong.
There is one final option which is to switch to a back three.
Mikel Arteta has admitted he expects that Ben White will be fit for the derby.
“I think so. He’s starting to do a little bit of work on the pitch. We want everyone available,” said Arteta.
With that in mind, and due to Rob Holding’s impressive displays, Arsenal and Arteta could opt for a three at the back system.
This would match up with how Antonio Conte plays and give the Gunners the necessary protection and security to avoid overcommitting in attacks.
Holding would be flanked by Ben White and Gabriel Magalhaes, with Takehiro Tomiyasu and Nuno Tavares operating as wing-backs.
That would also allow for more numbers in dealing with the Spurs wingers.
Whatever the theories might be, the reality is simple.
Arsenal win and Champions League football returns to the club next season.
A serene simplicity that sets up one of the most important North London Derbies of the millennium.