Chelsea coach Sarri: Morata needs goals to revitalise fragile confidence

Morata, 25, scored freely in the first few weeks after joining Chelsea last year but has appeared short of confidence recently. He has scored once this season, in August's win over Arsenal.

"Alvaro has to gain confidence with one, two, three goals," Sarri said following the 1-0 win on Thursday, during which the Spain and Chelsea striker missed a number of chances.

"I am not able to give him confidence," he said in comments carried by the British press on Friday. 

"I hope for him that in the future I can try to help him, but the confidence can become only with goals.

"I have to say also, for maybe the first time in this season Alvaro was ready in the box. He was on the ball and was active."

Chelsea have won all five of their Premier League games so far under Sarri ahead of Sunday's trip to West Ham, and Willian's seventh-minute strike was the difference in Greece.

But the 59-year-old Italian bemoaned his side's inability to finish off their opponents.

"When it is time to kill the match we have to kill the match," he said.

The one major blot was a stoppage-time shoulder injury for Pedro, which could rule him out of Sunday's trip to West Ham.

"I don't know exactly the situation," said Sarri. "I have spoken with the doctor but only for a few seconds. The doctor told me that probably it's not a very serious injury."