Italian Raffaele Marciello has been named Sauber's test and reserve driver for next season.
The 20-year-old won the European F3 championship last year and is a member of Ferrari's driver academy.
"We will give Raffaele the opportunity to become familiar with Formula 1, which also includes him taking part in some free practice sessions," said team boss Monisha Kaltenborn.
Marcus Ericsson and Felipe Nasr will be Sauber's race drivers in 2014.
Marciello, who will race in Formula 1's feeder series GP2 next year alongside his Sauber duties, got his first taste of a Formula 1 car last month, when he tested with Ferrari in Abu Dhabi.
"I really think that this is the best choice for my future career," said Marciello, who started his racing career in karting in 2005.