I don't know if this is different because I'm in a historical sim (currently in 1987) but every injury in my minor leagues is only able to go on the 10-Day disabled list (which was abolished in 1984) UNLESS they are on the MLB club's 40-Man Roster. Then a 60-Day DL is possible AND free's up that player's spot on the 40-Man Roster.
I first read the OPs unofficial guide several seasons back in my saved game. I liked a lot of what is proposed and I've tried to follow jpeters1734's system as best as I could. Unfortunately, I have not been very successful in following the guide as closely as I wanted. I'm going to try and layout a scenario similar to mine.
MLB Team has 3 SP's and 1 CL you wouldn't replace. C is solid. 1B is solid. SS is solid. 3B is solid. LF is solid. CF is solid but aging. So, those 6 position players ain't goin' nowhere!

While RF and 2B aren't rock-solid, I do have 2 awesome Utility players who are fast and can each play 5 positions. But, as much as I value them, they could be replaced. Overall, I'm left with 3 Pitchers, 2 Infielders and 3-4 Relief P's that
could be replaced by better players.
AAA Team has some great players too! An LF, CF & 1B are awesome prospects, but not so awesome that I would replace tried & true MLB'ers. So they have to play AAA until I feel like replacing an MLBer or two. I have a 2B who should be in the majors on any team, but not good enough to warrant losing one of my MLB util players, not yet. 2 of my AAA SP's could be brought up and probably will at the half-way point. My AAA rotation is going to be awful, but MLB is what matters, right?
AA Team has 1 really good SP, 1 Good SP, and 2 really good pos. players. SS & RF.
Class A Advanced Team has a HoF CF. Everything else is anybody's guess. As you can see, I've got many roadblocks to making my MLB squad. That's a good thing! Unfortunately, that means my AAA talent is going to live in AAA-land for years, barring injury. Some AA talent will make it to AAA, but I don't want to promote 'em just to bench them. I'd rather they keep playing ball all season in AA, most likely.
If you have a really good MLB team you just can't promote according to a schedule. Most of those really good MLB'ers are going to be playing for years to come. Again, that's the goal, right? If any of my young players turn into anything worthwhile by the time they're in A+ ball their progress is going to slow because of the players ahead of them (unless they play different spots, of course). Pitchers, not so much...you can never have too much pitching, right?
Is it recommended to just cut good AAA players who have aged and appear to be blocked due to MLB talent? I've got 26 and even a couple of 27-year-olds still in AA because of the cascading effect of having better players ahead of 'em...Even though that 26-year-old is really good, his AAA and MLB. If my MLB SS blows up his arm and knee I'll have that AAA SS replace him and feel ok that I'm not losing much if anything at all. Then, finally, my AA SS will move up to AAA. In time, he'll be playing SS at 32 years old in AAA if a better, younger player doesn't come along. Is it sometimes better to cut someone like that recently promoted AAA SS so I could put a much younger AA SS in his place, even though that AA SS is 1.5 stars and the old SS is 3 stars? Who knows, maybe with every day playing the 1.5 SS might progress to 2.5 or maybe even 3, if lucky.
I hope I haven't written an unreadable pile of dog-doo. Hopefully, anyone who hasn't fallen asleep yet will get the gist of what I'm asking.

I'd love to hear people's thoughts on this.
