The Italian defender started at left-back and produced a solid overall display before he was forced off in the 70th minute with a suspected ankle problem.
The 23-year-old landed awkwardly after being barged out of the way by Eguinaldo and needed to be substituted, with teenager Myles Lewis-Skelly brought on in the second half.
Arteta conceded he didn’t know how serious the injury would be, as the Spaniard now faces an anxious wait to see if he will be fit for their next game.
“Riccy, I don’t know, he felt something and could not continue playing. A bit of a worry,” Arteta told Amazon Prime Sport.
On whether Saka would be available against Liverpool on Sunday, he added: “I don’t know, so he wasn’t able to train yet. That’s unlikely,” Arteta said.