Dropping him to the bench would also achieve that but I don't believe he isn't
trying. It's his first season in the Premier and he's not use to the pace. Also all the responsibility to score is on him as we don't really have a backup. Long should be given a go but he's not exactly prolific.
I don't think he's not trying either, but as a CF he hasn't played well. If Long is fit, time to play him.