With Max Verstappen clinching his third consecutive drivers' title and Red Bull comfortably retaining the constructors' championship, the future of Sergio Perez remains in doubt.
And Horner admits that with a number of drivers out of contract in 2024, some have offered up their services in return for no payment.
Christian Horner is happy with the Red Bull stableDrivers are queuing up to drive for Red Bull and some have even offered their services for free
Horner: There are no guarantees
"2024 is a big year," Horner told Sky Sports. "A lot of drivers' contracts are coming to a close. We've got great talent in our own stable. Of course the car is very attractive for other drivers to want to be in."
When questioned about parallels to Ayrton Senna's offer to drive for Williams without payment back in the early 1990s, Horner confirmed that similar gestures had been made.
"There's been a little bit of that, but there's no guarantees of anything.
"Checo is our driver. If he does well, we'll want to keep him for 2025, but it's all about how he performs in relation to his team-mate."