Although Horner expects the usual contenders to be in the mix in 2022, he admits that the pecking order is difficult to predict.
The Albert Park circuit is undergoing quite a few changes ahead of the 2022 Australian GP, the third race of the Formula 1 season.
Both Mercedes and Red Bull fell short in getting right a key aspect of their 2022 Formula 1 cars, as they failed the FIA's crash test.
Valtteri Bottas left the Mercedes F1 team at the end of the 2021 season, having played a part in the team winning 5 constructor's titles.
Sergio Perez played a key role in Max Verstappen's world driver's championship win in 2021, often holding up rival Lewis Hamilton.
Sainz gave no hints about his new car during Ferrari's warm-up sessions at Fiorano this week, but he did offer a good tease.
The turbo-hybrid era in F1 has almost entirely belonged to Mercedes, with the team winning eight consecutive Constructors' Championships.
With both Leclerc and Sainz putting some early mileage on their 2022 clocks, Thursday saw the return of one of Formula One's strongest driver lineups.
The 2021 season ended in questionable circumstances on the final lap of the Abu Dhabi Grand Prix, 22 races after it began.
On the evening of February 11, the MCL36, which will be driven by Lando Norris and Daniel Ricciardo, will be unveiled in an online event.