I know Isak is the obvious answer, but he's got excuses. No summer training, playing in a struggling team, was finally getting in shape and then got a bad injury. I'm sure next season will be a different story.
But Gyokeres?
Playing for the best team in the country. And he still looks awful. He's a Championship player isn't he. Just miles from the level needed. Says a lot about how easy Arsenal have found it that they're walking the league despite him.