A player is eligible for the offseason Rule 5 draft if he is not on the 40-man Major League Roster if he was 18 or younger when he first signed a pro contract and this is the fourth Rule 5 draft since he signed or if he was 19 or older when he first signed a pro contract and this is the third Rule 5 draft since he signed.
Thus, Major league teams must protect players on their 40-man rosters within three or four years of their original signing. Those left unprotected are available to other teams as Rule 5 picks.
A player drafted in the Rule 5 draft must remain in the majors, be it on the 25-man roster or the disabled list, for all of the following season, or the club that drafted him must return him to his original club. Since a player to is returned must first be place on waivers, a third club can claim the player. The claiming club would then be responsible to the same rules placed upon the team that drafted him in the Rule 5 draft.
Making this clearer:
After a player has played three full professional seasons, he must protected on the Major League Team's 40-man roster or he becomes available to be selected in the Rule 5 draft. If after the three years he is placed on the Major League Roster, the club then has options on that player.
A player on the 40-man roster but not on the 25-man Major League Roster is on what is called optional assignment. A player on optional assignment has three option years, and can be sent up and down as many times as the club sees fit during those three seasons.
A player who has been in the Major Leagues for parts of three different seasons is out of options, and must clear waivers in order to be sent down beginning with his fourth big league season.
The Rule 5 draft will take place in December during the winter meetings. Occasionally a gem will be found such as Luis Ayala picked by the Expos in 2002, but more often than not the players picked up do not amount to much.
Donaldo Mendez, on the Padres list this season was a Rule 5 pickup in 2000.
The San Diego Padres 40 man roster:
Matt Bruback (RH)
Mike Bynum (LH)
Adam Eaton (RH)
Justin Germano (RH)
Trevor Hoffman (RH)
Ben Howard (RH)
Kevin Jarvis (RH)
Brian Lawrence (RH)
Scott Linebrink (RH)
Mike Matthews (LH)
Chris Oxspring (RH)
Jake Peavy (RH)
Dennis Tankersley (RH)
Rusty Tucker (LH)
Brandon Villafuerte (RH)
Kevin Walker (LH)
Jay Witasick (RH)
Ramon Hernandez (pending trade)
Mark Kotsay (expected to be replaced by Terrence Long in pending trade)
Gary Matthews Jr.