Simplify the following text for a Grade 9 native English-speaking person.
Original: As it turned out , Ricciardo and Hartley were to share test and reserve duties for both Red Bull , and sister team Scuderia Toro Rosso until the latter was removed from the Red Bull Junior team .
Simplified: Ricciardo became one of the test and reserve drivers for both Red Bull Racing , and the sister team Scuderia Toro Rosso