Meanwhile, Ricciardo has also been linked with a permanent exit from the grid having been bested by team-mate Yuki Tsunoda so far this season. So, what is in store for the 35-year-old?
With Ricciardo's future subject to regular discussion, Red Bull motorsport advisor Helmut Marko appeared to throw doubt over the continuation of one current star beyond 2025.
The 81-year-old, who is also in charge of the team's driver development programme, claimed that Liam Lawson would be in an F1 car in 2025.
The New Zealand racer replaced Ricciardo for five races in 2023 when the Australian was injured in a crash at the Dutch Grand Prix, and is touted to be the next driver from the Red Bull production line to get a full-time seat in F1.
This would likely come at the expense of Ricciardo or Perez, with Tsunoda seeming certain to see through the one-year extension to his RB contract into 2025.
However, Horner denied that Lawson would certainly be replacing one of the two at risk drivers.
"Nothing is fixed," he told Sky F1. "At the moment, we’ve still got a few weeks to make those decisions."
“Obviously we know the situation with Checo, and the contract that he has." Perez's contract was extended until 2026 earlier this year, though it is unclear what exit clauses the team has and how it could be cancelled early.
“With Daniel and Liam, there are options within their agreements that, obviously, we won’t talk about in public until things are concluded," Horner added.
He also later clarified to Sky Sports that Lawson could be 'rented' out to another team on the grid for 2025.