Since there seems to be some confusion about the actual post-season eligibility rules, here are the ones from an actual baseball person, 2007 Red Sox director of baseball operations, Brian O'Halloran:
"The position-player-for-position-player / pitcher-for-pitcher requirement is indeed now gone for substitutions prior to a series," O'Halloran wrote in an e-mail. "However, teams now are allowed to substitute for an injured player during a series. Such in-series substitutions are position-player-for-position-player / pitcher-for-pitcher, and the injured player cannot be active for the remainder of that series or the next series. Those substitutions also require MLB approval.
"The way substitutions (before a series) work in general is as follows: each team's initial pool of eligible players is the 25 players on its active roster at midnight on 8/31 plus any players on the 15-day DL, 60-day DL, suspended list, bereavement list, etc. So we have 28 players in this pool (25 plus Donnelly, Clement, and Mirabelli, all of whom were on the DL on 8/31). Any player in a team's pool who is injured when a given series begins can be substituted for. So if Mirabelli is healthy at that time he will not be eligible to be substituted for, as an example. But if any player of the 28 eligible guys is hurt at the beginning of a series, we could substitute for him. For example, with Donnelly being out for the year, we can substitute any player who was in our organization on Aug. 31 for Brendan. This substitute could be a pitcher or position player, and does not necessarily have to have been a September callup."
So, to substitute ANY player in the organization onto the playoff roster, all you need to have is someone WHO IS ELIGIBLE for post-season play.
That includes all players who, as of 8/31, are on:
- the active roster
- the 15-day DL
- the 60-day DL
- suspended list
- bereavement list
- military list
You can choose your 25-man team for a playoff series from that list.
If a player on your playoff team is injured, you can "substitute any player who was in our organization on Aug. 31."
So, if you had 25 people on the 60-day DL, you could choose ALL of them for your playoff team and then substitute, willy-nilly.
The position-player for position-player and pitcher for pitcher substitution is only for AFTER a playoff series has started and someone gets injured.
And yes, it position-player for position-player NOT some OF for OF/IF for IF belief.
Hope this clarifies things for everybody.