The 32-year-old German has been out of a job since Toyota dropped him from their Formula One team at the end of the season.
But Mercedes motorsport boss Norbert Haug is keen to get the six-time Grand Prix winner behind the wheel of one of their C-Class cars and has set aside a day for him to drive at the Portuguese circuit.
Former Jaguar and Red Bull racer Christian Klien, who announced last week that he was looking for a drive outside Formula One after missing out on a race seat with Force India for this season, will also test.
Season 2008
Schumacher: I'm not done yet
09/01/2008 AT 17:30
Mercedes have a seat in their works AMG team available following the retirement of Mika Hakkinen, who has raced for them for the past three seasons.
Season 2008
Mercedes keen on Ralf
17/01/2008 AT 14:24
Season 2008
Schumacher: I'm not done yet
09/01/2008 AT 17:30