The Brazilian defender started every single game for Arsenal last season but this time he was dropped for tactical reasons. Not because there was a better player instead of him, but because Arteta had a different game plan.

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"It worked really well," Arteta said after his side's 2-1 win over Nottingham Forest. "That's my job, to create bigger problems to the opponent and to the ones they are creating."

Last season, Arsenal were brilliant in taking Manchester City nearly all the way but there was a predictability about their team.

You knew who the back four would be, that Thomas Partey was going to be alongside Martin Odegaard and Granit Xhaka in midfield - and that Bukayo Saka and Gabriel Martinelli would occupy the flanks.

Against Nottingham Forest on Saturday, Arteta made just one change to his line-up but the whole team changed.

Gabriel went out, Partey went from midfield to defence, Kai Havertz went from the attack to midfield and in came Eddie Nketiah. Such a switch was almost impossible a year ago. Arsenal allowed themselves to play an attacking line-up which penned Forest in - the result being a 2-0 half-time lead and the game almost done.

Now, Arsenal are in a position where no one knows who out of Ben White, Jurrien Timber, Takehiro Tomiyasu or even Partey will play at right-back. Will Gabriel return next week? Will Declan Rice be a defensive midfielder next to Havertz, or an attacking one next to Partey or Jorginho? Leandro Trossard can play four positions, where would he fit in?

Partey's role in the first half was fascinating. In the first half, he took a throw-in quickly, like a right-back would, and immediately sprinted into the middle of the pitch, as if he was a central midfielder recovering back into position.

It mimicked Oleksandr Zinchenko's role last season - just on the other wing. It's another string to Arsenal's bow - do the Gunners invert their full-back from the right or the left. Or both?

The Gunners' variation is something to watch this season, especially as they balance the Champions League with what they hope is another Premier League title bid - but the game was almost done. One aspect Arteta must fix is a slight soft underbelly that Arsenal have.

Arteta's side were cruising in the game but one moment of concentration allowed Nottingham Forest back in through Taiwo Awoniyi's goal. Morgan Gibbs-White curling an effort over seconds later evoked memories of the two-goal leads dropped against Liverpool and West Ham last season - results which caused the title dream to start slipping away.

"The reality is we didn't concede much," Arteta assessed after the game. "But when you are running the clock down, it's a dangerous thing to do in this league.

"We have to be more ruthless, critical and pushy."

It was a reminder that this is still a young Arsenal team in terms. One season older, but at the moment Forest threatened to snatch a draw, there was only one Arsenal player on the pitch - Partey - on the field with a top-flight league medal to their name.

This was only one game and Arsenal got over the line. There are signs there is more about them this season in their bid to usurp Manchester City at the top.

But while Arsenal have more about them, Saturday's nervy ending proved their biggest challenge may just be how they overcome themselves.