By 1970s Gooner
Arteta should resist the temptation to start Saka in a left back or left wing back position.
Firstly he is so much more effective playing on the right wing in a 4 3 2 1 formation. He pushes the team forward with his runs and he also provides a real goal threat.
Secondly in order for Saka to be effective playing in Tierney's place, Arteta may need to revert to a 3 4 3 formation which would allow Saka to bomb forward.
However this means changing to a system that the players have become unaccustomed to which may create problems with the effectiveness of the team as a whole.
And lastly Slavia are likely to adopt a more conservative approach as they did very effectively against Leicester and Rangers. So when they do attack on the counter you need proper defenders to defend.
You will also need your creative players playing up front so that a maximum number of goal opportunities can emerge.
Leno
Chambers Holding Mari Cedric
Partey Xhaka
Saka Odegaard Smith Row
Lacazette
Yes please drop Aubameyang Mikel. And when Lacazette begins to tire bring on Martinelli as a centre forward.