The Gunners play in the Europa League group stages, and Luiz will not feature from the start or on the bench.
He came off during the team's 1-0 defeat to Leicester City in the Premier League with an injury.
"There is no chance [David Luiz will face Dundalk]," Arteta said during a press conference.
"He's a big doubt for the weekend too.
"Willian is back in training, he might be involved at some stage.
"Bukayo Saka is fine, it was a knock, but he's fine."