As Arsenal took to the field for their Premier League clash with Sheffield United at Bramall Lane on Sunday Mikel Arteta was able to spring a surprise before the game had even begun.
When the team sheet had been announced it had seemed as though Bukayo Saka was going to be moved back into the back four to play left back.
The 19-year-old had broken into the Gunners first team in that position last season and provided the next best alternative to the attacking threat missing since Kieran Tierney had been ruled out with a knee injury sustained against Liverpool, so asking him to reprise the role appeared to make sense.
But as the team set up in formation before kick off it quickly became apparent that that wasn't going to be the case.
Instead Granit Xhaka was chosen to fill in on the left hand side of a much changed back four that included Calum Chambers, Pablo Mari and Rob Holding.
While it is not totally unheard of for the Swiss international to play in that position - he did so on a few occasions during the early part of Unai Emery 's reign - it was still something of a shock to see him return to a position he has never played under Mikel Arteta.
And yet Xhaka was still able to put in a solid performance.
While it cannot be argued that he even came close to replicating the attacking threat provided by Tierney's aggressive overlapping runs, the 28-year-old was able to excel in his own unique interpretation of the position.
Xhaka spent most of the game in a deep position, with his average place on the pitch being just to the left of the centre circle within Arsenal's own half.
It was more or less what he does as a central midfielder when he drops in alongside the centre backs to provide defensive cover for the mauarauding runs of Tierney, and was crucial for allowing both Dani Ceballos - who spent much of the game in the inside left channel of the attacking third - and Gabriel Martinelli to have impressive games.
The Swiss midfielder was also effective in possession managing more passes (78) than anyone on the pitch, and completing a higher percentage (94.9%) of balls than any of his teammates who started the match.
When asked to explain the decision in his post match press conference Arteta revealed it had been taken in order to prevent an attacking threat that Sheffield United had to offer, and hailed Xhaka's willingness to adapt for the good of the team.
"He had a specific role today for the game because we believed they were going to try to do something," said the Spaniard.
"He had the right qualities to develop that role. He did that really good.
"It's a joy to work with him because you ask him to play as a centre forward and his first reaction is 'yeah, yeah I'll do my best'."
However, before completing the answer Arteta dropped a bombshell that confirmed he will more or less have to rethink the entire way he structures the Arsenal attack.
"I think today he [Xhaka] had a really strong performance," he continued. "And with Kieran probably out for the season it gives us another option."
Initially the prognosis had been that Tierney would be out for 4-6 weeks which would have potentially seen him back in time for the second leg of the Europa League semi finals - if Arsenal make it that far - and the last three games of the Premier League season.
But now with the revelation that the Scot will likely be out slightly longer, it seems as though finding a solution at left back for the business end of the season is something the Gunners are going to have to do.
After his performance against Sheffield United many have suggested that continuing to play Xhaka in the position could be an option in the coming weeks.
However, as Arsenal now turn their attention to their most important game of the season in the Europa League second leg against Slavia Prague. they may be better served looking elsewhere.
The Czech champions top goalscorer and biggest attacking threat is right winger Abdallah Sima.
While the Senegalese forward started the first leg at the Emirates in the centre forward position, the fact that a the more orthodox 'number 9' Jan Kuchta had plenty of joy up against the Gunners' underwhelming back four after coming on for the latter stages of the game may well encourage Slavia's boss Jindřich Trpišovský to restore Sima to his preferred position out wide.
If this does turn out to be the case as Arsenal push forward to try and score the goal they now need to go through, after conceding a last minute away goal in the first leg, Xhaka at left back could well end up exposed by Sima's devastating pace.
The Swiss international has several strengths, but mobility isn't one of them and some his worst moment's in a Gunners shirt came as Unai Emery's kamikaze tactics left him exposed on the counter during the latter part of the Spaniard's reign in North London last season.
Instead of playing Xhaka in defence again Arteta would probably be better served moving the 28-year-old back into midfield and playing a regular defender like Cedric in his back four to deal with the threat Sima poses.
From an offensive point of view a more mobile presence at full back such as the Portuguese international would likely be able to help Arsenal take greater advantage of the space left in behind Slavia's attack-minded right back Alexandre Bah that Nicolas Pepe was able to capitalise upon so effectively in the first leg.
Xhaka undoubtedly has the qualities to excel when he is allowed to have the game in front of him and this was the case when he played at left back on Sunday at Bramall Lane.
But with the stakes so high the Gunners can ill afford to have any defensive liabilities in a game were conceding goals could prove catastrophic to their Europa League ambitions. It is also worth considering that Slavia will almost certainly offer far more when it comes to pressing high up the pitch than Sheffield United did.
There are occasions were playing Xhaka at left back makes sense and knowing he is capable of doing so with minimal fuss is a useful tool for Mikel Arteta to consider between now and the end of the season. But Thursday night's vital game is most definitely not one of those. The Arsenal manager would surely be better off playing Cedric in the position instead.
