Turner has been Arsenal’s ‘cup goalkeeper’ this season, but a groin injury has prevented him from playing since October 20.
The USA international has missed Arsenal’s last two Europa League games, and he has to settle for a place on the bench against Brighton tonight.
Cedric Soares makes his first start to the season, while Rob Holding and Kieran Tierney start too.
Takehiro Tomiyasu does not play after coming off injured against FC Zurich last week, but his injury is not thought to be that serious that it’ll keep him out of playing at the World Cup for Japan.
The Arsenal midfield completely changes from Sunday’s win over Chelsea as Albert Sambi Lokonga, Fabio Vieira and Mohamed Elneny all come in.
Eddie Nketiah leads the line and Reiss Nelson comes into the attack too, while 19-year-old Marquinhos gets a rare start.
Arsenal XI (4-3-3): Hein, Cedric, Saliba, Holding, Tierney; Elneny, Lokonga, Vieira; Marquinhos, Nketiah, Nelson
Subs: Turner, White, Gabriel, Zinchenko, Partey, Xhaka, Ødegaard, Martinelli, Jesus
Wednesday 7.45pm GMT
Venue: Emirates Stadium