1. No player may be optioned to the minors prior to the start of Spring Training.
2. An injured player cannot be optioned to the minors.
3. A "Rule 5 Player" cannot be optioned to the minors until Rule 5 restrictions have been removed.
RULE 5 PLAYERS ON CUBS 40-MAN ROSTER
4. A "Draft-Excluded Player" cannot be optioned to the minors any earlier than 20 days prior to MLB Opening Day.
DRAFT-EXCLUDED PLAYERS ON CUBS 40-MAN ROSTER
Arismendy Alcantara, INF
Dallas Beeler, RHP
Zac Rosscup, LHP
5. A player who has accrued at least five years of MLB Service Time cannot be optioned to the minors without his consent. The player can waive this right, but the waiver cannot be signed more than ten days prior to MLB Opening Day, the player has the right to designate in advance which minor league team to which he can be assigned, and the waiver automatically expires if the player is not optioned to the minors within 45 days or by the 45th day of the MLB regular season (whichever is later).
CUBS WHO MUST GIVE PERMISSION BEFORE THEY CAN BE OPTIONED TO MINORS:
Ryan Sweeney, OF
Carlos Villanueva, RHP
6. A player who is optioned to the minors generally must remain on Optional Assignment for at least ten days. (A player optioned to the minors during Spring Training generally must remain on Optional Assignment for the first ten days of the MLB regular season). The only exceptions are if the player is recalled as the "26th man" for a day where a doubleheader was scheduled at least 48 hours in advance, or is recalled to replace a player on the 25-man roster who is placed on an MLB inactive list (Disabled List, Bereavement List, Paternity List, Restricted List, et al), or if the player's minor league season is over, or if the player is traded.
7. All players on Optional Assignment to the minors must be recalled no later than the day after the conclusion of the MLB regular season.