I understand that in order for a player to be eligible for the playoff roster he must be on an owners 40 man roster and in the major leagues.  Is there a particular day that the person must be in the majors (roster expansion day) or can it be anytime up until the end of the season?  The reason I ask is that I've got some good prospects at AAA already on the 40 man but I've got a pat ML roster.  I want the AAA guys to continue playing everyday at their level but I want them available for the playoffs in case someone is injured.   I didn't see any info in the help guide or the FAQ's regarding this specific question so info is appreciated.

A player must be on the 40, but not necessarily in the majors, when the roster expansion day AM cycle 1 runs, to be eligible for the playoffs.

Thank you for the info.