Simplify the following text for a Grade 10 native English-speaking person.
Original: Before the 1951 season , O'Malley reportedly offered Robinson the job of manager of the Montreal Royals , effective at the end of Robinson 's playing career .
Simplified: Before the 1951 season , O'Malley offered Robinson the job of manager of the Montreal Royals starting at the end of Robinson 's playing career .