Instead of celebrating, Morata, who has struggled for form, appeared downbeat after scoring the decisive goal to maintain the Blues’ 100% start in Group L.
“It’s very important for him to score,” Sarri said. “He played a very good match. I think Alvaro can restart from this performance.
“If after a goal he wants to cry, I hope to see him cry very often.”
Despite dominating both territory and possession, it took the second-half arrival of substitute Eden Hazard to add spark to a Chelsea team frustrated for long periods.
And Morata, who had earlier missed a glorious chance, capitalised on some extra space by sweeping in Willian’s flick from a Cesc Fabregas pass. It ended a miserable run for the 25-year-old, who had managed just one goal from nine previous outings this season.
The hosts were unable to add to their lead and had goalkeeper Kepa Arrizabalaga to thank for preserving the three points when he turned away Istvan Kovacs’ drive late on.
The result ensured the 2013 Europa League winners top the group with six points, having beaten PAOK Salonika in Greece in their opening fixture last month.