I've put together a spreadsheet, as part of my organizational references that I've been working on, regarding this offseason's 40-Man roster.
Here is a first draft, containing the current roster (with offseason status) and all the eligible Minor League free agents and Rule 5-eligible players within the system that need added to the roster or may be taken in the next Rule 5 draft.
40-MAN ROSTER GRID
I have not included, in the right column of minor league possibilities, players such as Devin Mesoraco, Dave Sappelt, Donnie Joseph, etc. who may wind up on the roster at some point this next season, but are not likely to be reserved this November 20 when the protection lists are due to Major League Baseball.
Each team reserves 40 players under the Majors (obviously), 38 for AAA, 37 for AA and 35 for all other classifications. Essentially all Rule 5-eligible players can be drafted at a level higher (or more) than they are reserved on November 20. The Rule 5 draft takes place at the winter meetings in mid-December in three phases: Major League (for all players in the minors not on a 40-man roster), AAA or 3A phase (for players reserved at AA or below) and 2A phase (for players reserved at A or below).
Players become eligible for their 4th Rule 5 draft since the date of signing their first pro contract. Players 18 or younger on the June 5 preceding their first contract get an additional 5th draft before becoming Rule 5 eligible.
So, if my math is correct, while this is not an official list, here are the 39 players I've concluded are currently Rule 5 eligible for the Major League phase:
Further, players that have been assigned outright by their Major League club (see Micah Owings) who's minor league contract has expired become free agents. Even if a club re-signs these players, they are still eligible for the Rule 5 draft if not re-added.
RP AGUIDO GONZALEZ L L 24
RP ANDREW BOWMAN R L 24
SP BEN JUKICH L L 27
3B CARLOS MENDEZ R R 24
C CHRIS DENOVE R R 27
SP CLAYTON SHUNICK R R 24
SP CURTIS PARTCH R R 23
SP DALLAS BUCK R R 25
1B DANIEL DORN L L 26
RP DANIEL GUERRERO R R 25
RP DOUG SALINAS R R 21
1B ERIC EYMANN R R 26
RP EZEQUIEL INFANTE L L 22
2B JAKE KAHAULELIO R R 25
SP JAMES AVERY R R 26
RP JEFF JEFFORDS R R 25
RP JEREMY HORST L L 24
SP JORDAN HOTCHKISS R R 24
C JORDAN WIDEMAN R R 21
2B JOSE CASTRO S R 23
2B JOSE GUALDRON R R 23
RP JOSEPH KREBS L L 26
SP JOSH RAVIN R R 22
RP JUNIOR MARTINEZ R R 24
OF JUSTIN REED L R 22
OF KEVYN FEINER R R 23
SS KRIS NEGRON R R 24
RP LEE TABOR L L 25
SP MATT KLINKER R R 25
1B MICHAEL GRIFFIN R R 26
SS MIGUEL ROJAS R R 21
3B MIKE COSTANZO L R 27
SP SCOTT CARROLL R R 26
RP SCOTT GAFFNEY R R 24
OF SEAN HENRY R R 25
OF TODD FRAZIER R R 24
SP TRAVIS WEBB L L 26
RP TZU-KAI CHIU L L 23
SS ZACK COZART R R 25
Minor league players initially sign 7-year contracts, covering all or portions of 7 different minor league seasons. If these players become free agents, they too are Rule 5 eligible even after signing for the following season. Subsequent minor league contracts, or contracts signed by players with previous Major League experience often sign multi-year deals, though these minor league contracts are not published. Therefore, I always assume 7 years for the first contract and 1 year deals for any player signed thereafter.
With that in mind, my tentative list of minor league free agents that the Reds have to tend to this offseason:
De La Vara (who the Reds signed this August after he was released -- for the second time this season mind you -- by the Tigers), may have additional seasons covered by his Minor League UPC, but I'm unable to verify. I'll assume not, for now. He was actually drafted in last year's Rule 5 draft by Houston, but returned to Kansas City prior to the season as Houston decided they had too many LHP specialists. Yarbrough is a former Cardinals' third-round pick.
SP MICAH OWINGS R R 27 ASSIGNED
SP JUSTIN LEHR R R 33 FREE AGENT (C)
SP DARYL THOMPSON R R 24 FREE AGENT (C)
RP JERRY GIL R R 27 FREE AGENT (C)
RP JASON ISRINGHAUSEN R R 38 FREE AGENT (C)
P CHAD REINEKE R R 28 FREE AGENT (C)
C WILKIN CASTILLO S R 26 FREE AGENT (C)
RP JESUS DELGADO R R 26 FREE AGENT (D)
RP FEDERICO BAEZ R R 29 FREE AGENT (D)
RP GILBERT DE LA VARA L L 25 FREE AGENT (D)
RP RUBEN MEDINA R R 24 FREE AGENT (D)
P ABE WOODY R R 27 FREE AGENT (D)
C BRANDON YARBROUGH L R 25 FREE AGENT (D)
RF DENIS PHIPPS R R 25 FREE AGENT (D)
Note above that the only difference between Free Agent (C) and (D) is the C players have Major League experience.
As for the 40-Man Roster itself, the Reds currently have 43 players and need to dwindle that number down to 40 (or less) by November 20.
Free Agents Mike Lincoln, Russ Springer and Willie Bloomquist seem to be the perfect fits for that task.
Step 2 for me: find room for Matt Klinker, Doug Salinas, Zack Cozart and Todd Frazier at very least. I know some may be surprised by Salinas, but I'm pretty high on him. Conservatively though, the Reds will need to find 3-5 spots, especially if Danny Dorn is added. I suspect that will only happen if Gomes is out the door or the Reds will not be keeping either Laynce Nix or Jim Edmonds.
So let's assume four spots (though others may disagree on the fourth).
We can safely assume Aaron Harang's option won't be picked up. There's a good chance Corky Miller will again be outright assigned. I doubt the Reds pick up the Orlando Cabrera option. Jim Edmonds is likely to retire. So there's your four.
Sam LeCure and Matt Maloney are non-tender candidates. Further, Miguel Cairo may not be re-signed. There are three more possible spots. I'm guessing that Dorn and any outside OF possibility shall be tied to the futures of Nix and Gomes.
One last thing to consider: Homer Bailey, Carlos Fisher and (if healthy) Jose Arredondo will need to make the club next year. The three of them are out of options.
OK that's all I got for now. If anyone sees any additions/subtractions/corrections with the Rule 5 list, by all means let me know. I feel like it's pretty accurate, but given there are well over 275 players in the organization, I may have made a mistake or two with my database.