Aston Villa and Tottenham are £7 million apart in their valuations of the star midfielder, reports the BBC.
Spurs are hoping to sign the 22-year-old before transfer deadline day, but their offer has yet to meet Villa’s asking price.
Grealish apparently wants to take the next step in his career and ply his trade in the top division.
The former England Under-21s star scored three goals and provided six assists in 31 matches last season.
Sarri also revealed he expects Eden Hazard to remain at Stamford Bridge after the Belgium international made his first Blues appearance since Russia 2018.
Belgium international Courtois has been reported to have stayed away from the London club following World Cup duty with Belgium amid speculation of a move to Real Madrid.
“I don’t know in this moment,” Sarri told a press conference after Chelsea’s 5-4 win on penalties at Stamford Bridge when asked of Courtois’ future.
“I want to speak with my club and then we will decide about it. I am here to talk about this match.”
Chelsea are reported to have sealed a world record £71million deal for Athletic Bilbao goalkeeper Kepa Arrizabalaga, but Sarri refused to be drawn on any details of the potential signing.
“If I don’t know anything about Courtois, I don’t know anything about Kepa, of course!” the Italian said.
When pressed on 23-year-old Kepa, Sarri added: “I saw him one year ago. My first impression was that he is a very good goalkeeper, very young, but very, very good.”
Hazard, whose future has been in doubt all summer, was given a rapturous reception by Blues fans during their side’s penalty shootout win against Lyon and Sarri said he had “no problem” with the midfielder.
Sarri added: “We have spoken two or three times in the last two days. Hazard’s problem is not present now.”
Courtois was handed an extended holiday after finishing third at the World Cup with Belgium and was expected to return to the Blues’ Cobham training base on Monday, but did not attend.
Reports suggested he was also absent on Tuesday, having told Sarri he wanted to leave the club before Thursday’s transfer deadline.
Should Courtois – signed from Genk in July 2011 before spending a three-season loan spell with Atletico Madrid – not resume training with the Blues, he is likely to face an internal disciplinary meeting and the potential of a fine of up to two weeks wages.
The likes of Kepa, Jan Oblak of Atletico Madrid and Stoke’s Jack Butland are potential replacements should Courtois depart, but all parties are up against the transfer deadline to get any potential deals completed.
Chelsea, meanwhile, could also be set to make another addition to the squad with a loan deal for midfielder Mateo Kovacic from Real Madrid, according to reports in Spain.
City had made the recruitment of a defensive midfielder a priority but, after losing out on Jorginho to Chelsea, they may not head back into the market before Thursday’s transfer deadline.
City manager Guardiola does have some other options in the position, which could include deploying central defender John Stones in a midfield role. The England international briefly played in a more advanced position during Sunday’s Community Shield win over Chelsea at Wembley.
Asked if Stones could play there again, Guardiola said on Sky Sports’ Premier League Launch Show: “I don’t know, I didn’t put it in a training session. It was 10-15 minutes.
“We have Fernandinho, (Ilkay) Gundogan can play there. We don’t have many. I think we are not going to make any signings more this season.
“John, for the quality and personality he has, he is a tall guy, I think he can play there but I don’t know because we have never tried before. We will see during the season.”
City won the title with a record 100 points last season. Guardiola does not expect that tally to be beaten but is determined to keep driving City towards greater heights.
The former Barcelona boss said: “People say, ‘Can you improve on 100 points?’ – I say no. We are not here to do that.
“But individually the players can improve. Of course we can improve. If I felt we could not improve the team I would call my chairman and say, ‘OK, I leave’.
“We believe we can do better, dominate more and we will try to do it. Is it going to happen? I don’t know but we believe we can do it.”
City failed to mount strong title defences after their last Premier League successes in 2012 and 2014 but captain Vincent Kompany claims the feeling is different this time.
Kompany said: “I’ve got to be honest, there was a feeling when we’ve won the league (previously), you came back in to the training sessions and everybody was a little bit less (intense), a little bit more smiles and happiness, but a little bit less committed.
“Teams that actually wanted it more could hurt us. I came in (to training) this time and it’s completely different.”
Team-mate Kyle Walker, who cut short his summer holiday to return to training ahead of the Community Shield, spoke about his hunger to deliver again.
Walker had just two weeks off following England’s run to the semi-finals of the World Cup.
The right-back said: “I had the option if I wanted to come back later I could, but I wanted to be involved.
“I left Manchester City at the end of last season in a good place and I wanted to pick up where we left off.”