Saka, who has scored five goals and has 10 assists in the Premier League this season, departed midway through the first half and left the stadium on crutches and must now be a serious doubt for the holiday fixtures.
"It's difficult to guess now. They have tested him but difficult to say how bad it is," is all Arteta would say.
Jesus looks like a man re-born after seemingly forgetting how to score. He fired home after six minutes and smashed his second into the top corner after 14 minutes to restore Arsenal's lead following Ismaila Sarr's leveller.
He almost made it back-to-back hat-tricks when his header hit the post and Kai Havertz followed up to make it 3-1 before halftime and really should have done so when he failed to score from close range in the second half, seconds before Gabriel Martinelli made it 4-1.
"At one point I was feeling (pressure) but still I never doubted my quality," Jesus told the BBC. "I never doubted I can score goals. Obviously when you are having a bad moment you have to keep your mind strong, and that's what I tried to do.
"Sometimes I know when I played and leave with a smile on my face everything is different because I am grateful to God, he's great with me and it's impossible to do it without him."