Speaking to reporters in Seattle ahead of Belgium's Group G opener against Egypt on Monday, Courtois reflected on a long international career that has spanned 109 caps since his 2011 debut.
"I don't know if it's the moment to talk about it, but there's more chance that I won't continue with the national team after the World Cup than that I will. I'm 34 and I have to think about my body. I want to play at a high level for many years. I think now is the time to pass the torch to a new generation. They are ready."
On his club future, Courtois was equally direct about his preference.
"For me, the ideal would be to be able to finish my career at Real Madrid."
He explained the contractual framework that gives him confidence about his position at the Bernabéu.
"At Real Madrid, the principle is that from the age of 30, the contract renews year after year, so I'm quite relaxed about it. If I keep performing as I have been, a renewal won't be a problem. But Real Madrid is a top-level club and, at some point, they will also have to think about a successor."
Courtois also reflected on the lasting impact of the ACL injury he suffered in the summer of 2023.
"When I tore my cruciate ligament, I started thinking about the future, because I felt those rest periods gave me strength. There was no pressure to play, for example, four important Champions League matches in two weeks. I could go to the gym so my body could recover. Even when I wasn't called up by the previous national coach, I noticed I recovered well during those periods."
Asked about working under incoming Real Madrid head coach José Mourinho — who managed Courtois at Chelsea between 2013 and 2015, winning the Premier League and League Cup together — Courtois offered a warm if knowing assessment.
"We also had our occasional friction, of course. For example, he benched me against Everton because I had launched two long balls from the wing in the previous match against Aston Villa. It was his way of provoking me. The following week, I was back in goal against West Ham and made five or six crucial saves."
He summarised the relationship simply.
"Mourinho is a very direct coach; I'm the same. Our relationship has always been very good."
Courtois noted that Xabi Alonso had also called him after his appointment as Real Madrid coach, though that tenure proved brief. He added that, for now, "all the players are mainly focused on the World Cup; the club takes that into account."
Belgium face Egypt, Iran and New Zealand in Group G. Whatever happens in North America, Courtois has made clear it may be the last time he wears the Belgian shirt — even as he expects to wear Real Madrid's for some time yet.