Britain's Auto GP champion Adrian Quaife-Hobbs will spend one day at Barwa Addax, while Simon Trummer and GP3 champion Mitch Evans be at work in the Arden garage.
That leaves just Ocean Racing Technology to confirm any drivers for this week's test.
Scuderia Coloni are also expected to participate in the session after all, despite having decided to exit the series after the 2012 season. They will field two of their 2012 driver, Daniël de Jong and Luca Filippi.
There's been no word so far as to whether a replacement team will take Coloni's spot on the grid for 2013, or whether the series organisers will opt to slim down the starting grid to 24 cars.