Post-season Roster

so who's eligible for the postseason roster on this squad? I'm pretty sure neither Jason Lane, Chase Headley, and Drew Macias are ineligible....
Here's the "active" roster according to padres.com. If it's accurate, and Bradley is out, Macowiak is hurt, and the guys I mentioned are ineligible, it looks like they're bringing 5 pure outfielders along.

I did a little looking and I guess playoff rosters won't be set for a few days. Here's one explanation I came across:

Playoff Rosters: Playoff rosters must be set at 25, not including disabled players, on August 31. For each player on the 60-day DL, teams may add players to the eligible list during the playoffs at the same position, provided that they were in the orginization on August 31. This is why some teams will bring up injured minor-league players and put them on the 60-day DL. Teams must choose 25 players from their playoff eligible list before each round of the playoffs.

One question I have is this: If a playoff roster is set at 25 "not including disabled players" (what? blind?), does that mean that once a player comes off the DL, they can return to the lineup at the expense of a position player? or are players on the roster at the end of the season set no matter what? I'm confused and my meds are wearing off.
Thanks for the helps.