With the player's consent, a player on the MLB 7-day DL may be assigned to a minor league club for rehabilitation purposes for up to five days (or maximum eight days for a pitcher), and a player on the MLB 15-day or 60-day DL may be assigned to a minor league club for rehabilitation purposes for up to 20 days (or maximum 30 days for a pitcher).
A player on a minor league "rehab" assignment continues to accrue MLB service time, and does not count against a minor league club's Active Roster.
A player on a minor league 7-day or 60-day DL may be assigned to Extended Spring Training for rehabilitation purposes prior to the start of the minor league "short season" in June, or to a "short-season" minor league club for rehabilitation purposes for up to 20 days (or maximum 30 days for pitchers) after the conclusion of Extended Spring Training. (If a player on a DL of a minor league club is assigned to a "short season" club for "rehab" purposes, the club to which the player is assigned must be in a league with a lower classification than the player's club). A minor league player on a "rehab" assignment does not count against the Reserve List or Active Roster of the club to which he is assigned. (There is no roster limit at Extended Spring Training).
A maximum of three "rehab" players may be assigned to any one minor league club at the same time, but there is no limit to the number of "rehab" players who may be assigned to Extended Spring Training.