"I hope Courtois will be our goalkeeper", he said.
The 26-year-old has a year to run on his current contract and has been continually linked with a move prior to the summer transfer window closing, with Real Madrid rumoured to be his most likely destination if he is sold.
"I spoke yesterday (Thursday) with him about his lateness, not about his future".
"I arrived here three weeks ago and I've never seen six players, so it's very hard", he told reporters at Wembley.
But Sarri says the Belgian, who returns on Monday from post-World Cup leave, must explain his ambitions in person before Chelsea consider accepting a bid for him.
According to some reports, an expired passport is the reason behind Willian's absence, but Sarri has branded the situation as unusual.
Spain, Portugal brace for record high temperatures amid scorching European heatwave
Ladbrokes also cut odds on August highs beating Britain's 38.5C (101.3F) record, set on August 10, 2003, at Brogdale, Kent. Following its hottest July in 250 years, rain showers gave Sweden some respite on Saturday across most of the country.
"My idea is to have two good goalkeepers, the two we have now, Marc and Jasper", he said. I want to hear from Courtois.
"I think David will be very important for the team, to support me".
"We have very good midfielders, but maybe a midfielder with different characteristics [would be a good fit]".
Sarri will not want to lose either player after watching his side slump to a defeat to City on Sunday.
"If he was available on loan I am pretty sure we would be knocking their door down to get him".
"It depends on the club [how long I will stay]", he said.