Hamilton is in the final year of his current contract and is yet to sign a new deal with Mercedes following their dreadful 2022 campaign and poor start to 2023.
Mercedes boss Toto Wolff admitted at the Saudi Arabian Grand Prix that Hamilton may need to look elsewhere in order to win a record-breaking eighth title if his current employers cannot provide him with a competitive car in the next year or two.
But Wolff stressed he is “absolutely confident” Hamilton would sign a contract extension with Mercedes beyond the end of the 2023.
Hamilton has been linked with a shock switch to Red Bull, Ferrari or even Aston Martin amid continued speculation surrounding his F1 future, but Horner said he “can’t see” the seven-time world champion joining his team.
“What Lewis has achieved in F1 is second to none,” Horner told Sky News. “But we’re very happy with the drivers that we have.
“They’re committed as a pair not only this season but the next season as well. So, I can’t see where we would be able to accommodate Lewis.”
Horner said he is expecting Mercedes to resolve the issues they are facing with their troubled W14 car and therefore cannot rule out Hamilton challenging his drivers for the title.
“I’m sure they’re going to sort their issues out – we’re certainly not writing him off yet,” he added.
“We’re hearing about big Mercedes upgrades, I’m sure Ferrari aren’t happy with their current position as well.
“So, we’re fully expecting things to converge quickly.”