Postseason Roster Eligibility Explanation

Just to be clear, I can't find the official postseason roster rules anywhere on the 'net. Information is, at best, sketchy. For whatever reason, MLB.com only has the official rules of gameplay, but not of rosters and everything that they involve.

The clearest explanation I've found, though I don't believe that it is entirely accurate, is this, taken from a Detroit Tigers blog that is asking the same questions about postseason roster eligibility rules that we are:

To be eligible for a team’s playoff roster a player must be on either a)the 25 man active roster, b)the disabled list, c)the bereavement list, d)the suspended list as of August 31st at midnight.

Now, I could be wrong, but I do not believe that this is all-encompassing. Unless things have changed in the last two years, which they may have, I am nearly 100% certain that teams have the right to set their rosters prior to every series, meaning that the entire 40-man roster is eligible, regardless of position. An injury does come into play, apparently. The rule was changed prior to the 2008 playoffs to make the deadline for a playoff series roster later. It used to be that the rosters had to be made official the morning that the series was scheduled to start, regardless of weather interference. Now, the roster for a specific series doesn't become official until the lineup card is handed to the plate umpire prior to Game 1 of the series. This means that, if Game 1 is rained out before it starts, teams can still change their official series roster.

Drew Goodman and George Frazier seem to get asked this question every Tuesday on "E-mail the Booth" night, and they always say that any changes to the roster have to be A) due to an injury, and B) position-for-position. That is correct, but from the best that I can gather, that is only the case if it is a change in the middle of a series. Prior to a series beginning, any injured player can be replaced by any player on the 40-man roster, regardless of position. In the case of an injury in the middle of a series, a player does not have to have previously been on the 40-man roster in order to be eligible. He could be moved on to the 40-man roster to take the spot of an injured player. The only qualifier here is that he must have been in the Club's organization prior to the August 31 deadline and finished the season in that Club's organization. This means that, hypothetically, if Jason Hammel were to be injured during a series, Tyler Matzek could take his spot (just a hypothetical for the sake of clarity). The team also needs to receive approval from the commissioner if such a change were to take place.

From a conglomeration of a lot of sources the best that I can gather is this: in order to be eligible for postseason play without an injury, a player has to be on the team's 25-man roster or any of the lists mentioned in the blocked quote above as of August 31 at 11:59:59 PM EST. I could be way off on this, but since I can't find the rule expressly laid out anywhere on the internet, this is the best explanation I could come up with.

Now, regarding Jason Giambi's postseason eligibility, I do believe that he is eligible for the postseason roster based on the "injury" rule. It's kind of a keyhole in the rule, and again, I'm not 100% certain on this, but in order to make room for Giambi and Paul Phillips on the 40-man roster, the Rockies recalled Greg Smith and Greg Reynolds and placed them both on the 60-day disabled list, meaning that, technically, Giambi and Phillips are replacing injured players on the 25-man roster. It's not in the postseason, but I believe that this counts toward postseason injury credit.

If someone manages to find the rule (again, the official rule is MLB Rule 40a) or a clear explanation, it would be great if you would let everyone know. I don't want to convey inaccurate information, but this is the best I could piece things together.