Chelsea face Manchester City on Sunday afternoon in the Community Shield as Sarri looks to kick off his Blues spell with silverware.
Courtois' future at Stamford Bridge remains uncertain, but Sarri hopes the Belgium goalkeeper will stay.
There is less bullishness about Thibaut Courtois, who has shown little interest in extending the contract that expires next summer, but all parties know a high-quality replacement goalkeeper must be secured before he is allowed to leave. AC Milan have been heavily linked but the Italian giants have reportedly been put off by a very steep £62 million price tag which may suggest that the 25-year-old has a future under Sarri.
And asked if he could see Courtois now leaving, he told talkSPORT: "I think definitely in Thibaut's case".
Violence flares over Zimbabwe poll
Observers say it could be a tight race, but the opposition has said it will protest if their candidate is defeated. Mr Mnangagwa's Government has accused Mr Chamisa and his supporters of inciting violence by declaring he had won.
But Sarri said: "There is not a Willian problem".
"It's important for me to continue with Chelsea, I am comfortable here and want to win new titles and trophies".
Conte began pre-season as boss before belatedly being sacked, with Sarri appointed a day later, on July 14.
'I spoke with him about his late arrival, not about his future, ' said Sarri.
Cesc Fabregas is doubtful for the game after picking up a knee injury in a friendly against Arsenal on Wednesday.