Chelsea boss Maurizio Sarri is happy Alvaro Morata is off the mark - but wants more.
Morata scored in Chelsea's 3-2 victory over Arsenal.
Sarri said: "It's very important for him. I am really very happy with him, but I think also Morata can do better in the future. He has to improve."
Eden Hazard produced the assist for Marcos Alonso's winner.
Sarri added: "He is a great player. In this moment Eden is not able to play for 90 minutes. Yesterday I thought it would be better for him to play 25 or 30 minutes when the intensity of the match is going down.
"In one week, maximum two weeks, I hope he will be able to play for 90 minutes."