Former Arsenal striker Alan Smith says they need to buy a new centre-half.
Smith felt they were exposed in defeat at Manchester City.
He told Sky Sports: I think you're probably looking through the heart of the team, through the centre.
We've obviously seen how they've suffered without Wiliam Saliba and the drop-off was quite drastic really, no manager would want to see that so they miss the Frenchman.
Thomas Partey has been a bit in and out this season, when Xhaka didn't play they missed him certainly.
There's been a lot of attention on Arsenal's central midfield, possibly Declan Rice coming. That's going to be a saga in the summer. Where's the West Ham midfielder going to end up, it looks like he's going to leave the Hammers.
'Possibly another forward to compete with Jesus, they've got Eddie Nketiah but I think the centre-half and the central midfielder that will start games.
[Jakub] Kiwior, the defender who came in in January, could develop into a very good player so that might be a bit premature because they bought one in Kiwior but Mikel Arteta didn't feel he was ready yet and Rob Holding got the shout."