Courtois missed Chelsea's 2-0 defeat against Manchester City in the Community Shield on Sunday while he continues to rest after the World Cup.
But the 26-year-old remained a hot topic at Wembley following his agent Christophe Henrotay's call for Chelsea to show "compassion" over Real's attempts to sign the star, whose two children from a previous relationship both live in Madrid.
Real are keen to replace their error-prone keeper Kaylor Navas and former Atletico Madrid star Courtois is top of their shopping list, with Henrotay saying the deal would be the "best option" for him.
Courtois has only one year left on his Chelsea contract, but the Premier League club are keen to hold onto him despite Madrid's reported £35 million ($46 million, 39 million euros) bid.
Courtois is due back for pre-season training on Monday, with the Premier League campaign starting for the Blues at Huddersfield on Saturday, and Sarri is ready to discuss the issue with his player.
Hinting he would be willing to sell Courtois if he confirms he wants to leave, Sarri said: "I have no reaction on the agent. I am not interested in the agent. I want to hear Courtois.
"If Courtois tomorrow will say the same to me, I have to speak to my club of course.
"I want only players with a very high level of motivation."