Post-Season Rosters

[Centerfield]

I just heard Howie say that post-season rosters have to be set by August 31. In other words, if you're not on the 25 man, you're not playing in October. Is that true? What if someone gets hurt in September?

[MFS62]

You can replace an injured player for the playoffs.

Later

[Frayed Knot]

Yes, but only with a player who was on your 40-man as of Aug 31.

So if Pelfrey, for example, were called up on Sept 7th he could still be put on the post-season roster as an injury replacement (like if Willets accidently drops a cinderblock on Glavine's toe).
But if you trade for someone on Sept 2 he could NOT be subbed for an injury.

Obviously, DL'd players like Cliff, Ramon or Petey are eligible even if still on the DL come Sept 1