Sauber will unveil their 2014 Formula One car online ahead of pre-season testing while Toro Rosso will take the covers off at Jerez.
Sauber, who will have Adrian Sutil and Esteban Gutierrez behind the wheel this season, will present their car to the world on Sunday 26 January.
The launch of the C33 will take place online via the team's website.
Meanwhile, Toro Rosso have joined the list of those opting to unveil at Jerez but will do so a day before testing.
The Red Bull junior team will take the covers off the STR9 on Monday 27 January with Jean-Eric Vergne and Daniil Kyvat both present.
Jan 24 McLaren MP4-29
Jan 25 Ferrari
Jan 26 Sauber C33
Jan 27 Toro Rosso STR9
Jan 28 Red Bull RB10
Jan 28 Mercedes W05
Jan 28 Caterham