Think he's a better option than Walker these days.
Ortega
Akanji, Dias, Gvardiol, Ake
Rodri, Kovacic
Benardo, De Bruyne, Foden
Haaland
Also, think with Kovacic available there's no need to rush Grealish back in a game like this. If Kovacic wasn't fit it might be worth bringing Jack in to steady the midfield ship but Kovacic brings a lot of control and composure anyway (and also has good ball carrying abilities much like Jack).
Will be very tough this one. Arsenal came into the 4-1 game last season defeated before the first whistle but their confidence is high this season and they'll be a different proposition. We're gonna have to beat them differently this time. We can definitely do it but they're a much tougher prospect this year.