First of all, Martinelli always in my team.
Then Arsenal should sell Vieira, Lokonga and arguably Jorginho and ESR too, but not sure OK about it yet as with the former two.
New midfield.
Keep Xhaka, Ødegaard and Partey.
Buy Caicedo... and then be practical buy Rabiot or SMS to compete with Xhaka and Julian Brandt to be other playmaker instead of Fabio Vieira alongside Ødegaard.
Move Tomiyasu to CB, he is a decent player. So Arsenal will need one RB... and the LB as well if Tierney is out.
Then Arsenal should sell Vieira, Lokonga and arguably Jorginho and ESR too, but not sure OK about it yet as with the former two.
New midfield.
Keep Xhaka, Ødegaard and Partey.
Buy Caicedo... and then be practical buy Rabiot or SMS to compete with Xhaka and Julian Brandt to be other playmaker instead of Fabio Vieira alongside Ødegaard.
Move Tomiyasu to CB, he is a decent player. So Arsenal will need one RB... and the LB as well if Tierney is out.