What is the Rule 5 draft and which St. Louis Cardinals minor-leaguers of note might be selected?

Today is the Thursday of the Major League Baseball Winter Meetings, which means that the Rule 5 draft will be held. Whereas the Rule 4 draft involves major-league clubs selecting amateur players who are not affiliated with any other big-league club, the Rule 5 draft involves teams selecting minor-leaguers. The Rule 5 draft is meant to prevent MLB clubs from squirreling away major-league-ready players in the minor leagues. To be eligible for selection in the Rule 5 draft, a player must meet the following criteria:

• Players not on a major-league team's 40-man roster; and
• Players who signed at the age of 18 and have played in five professional seasons; or
• Players who signed at at the age of 19 and have played in four professional seasons.

There are two phases to the Rule 5 draft: (1) Double-A, and (2) Triple-A. Each of the MLB clubs has the opportunity to select a player but they are not obligated to do so. Teams with 40 players on their 40-man roster at the time of the Rule 5 draft are not allowed to make a selection. The draft order is determined by record. Teams select in reverse order of how their major-league club placed in the prior end-of-season standings. So the team with the worst record goes first and the team with the best record goes last.

Once selected, a Rule 5 draftee is added to his selecting club's 40-man roster and the selecting team must pay the minor-leaguer's former club $50,000 for the player's rights. Due to the purpose of the Rule 5 draft, once selected, a draftee must stay on the selecting club's 25-man roster for the entirety of the next MLB season. If the selecting team does not wish to keep a player on its 25-man roster for that time period, it must offer him back to his former team for $25,000. A draftee's former team can reject him, which allows the drafting team to waive the player. The selecting team may also trade a Rule 5 draftee, but the same rules regarding roster placement applies to the team that trades for him.

When the eligibility criteria were different several years back, many more interesting players used to be selected—Johan Santana and Josh Hamilton come immediately to mind. However, MLB and the MLBPA altered the qualification standards, giving players an extra year (whether signed at age 18 or 19) before they become Rule 5 eligible. The rule change means that fewer compelling minor-leaguers are eligible for the Rule 5 draft. Consequently, you don't see as many players changing clubs, let alone difference-making talents.

Which Cardinals minor-leaguers of note are exposed for this year's Rule 5 draft?

Mike O'Neill

A no-pop walk machine, O'Neill's batting profile makes him a Perfect Snowflake of a minor-leaguer. However, his handedness (left) and lack of speed prevent him from playing third base, shortstop, second base, or center field. O'Neill's punchless bat makes him an unlike MLB corner outfielder. After O'Neill split 2014, his age-26 season, between Double-A and Triple-A. Given his age, defensive limitations, and offensive profile, O'Neill has likely become a non-prospect.

Keith Butler

We'll start with the most familiar name. Butler made it to The Show in 2013, throwing 20 innings for St. Louis, and made a second appearance last year. You may have caught one of the two MLB innings he threw in 2014, or perhaps both. Unfortunately, Butler's season was cut short by a torn ulnar collateral ligament (UCL), which needed replacement via Tommy John surgery. Butler's 2015 will likely be lost to injury, so the Cards have removed him from their 40-man roster, outrighting him to Triple-A. This leaves Butler unprotected in the Rule 5 draft.

Jordan Swagerty

The Cards selected Swagerty in the second round of the 2010 amateur draft out of Arizona State as a reliever. His was a profile that suggested he might quickly climb the St. Louis organization ladder to the majors. But Swagerty also had questions about his arm health and his professional career to date has unfortunately done little to dispel those worries. Swagerty's 2012 was lost to Tommy John surgery. Last year, Swagerty threw just 10 2/3 innings between rookie ball and high-A, thanks to lingering elbow issues that ultimately required a second surgery.

John Gast

Another pitcher with an injury history left unprotected. Gast made it to the majors in 2013, but suffered a shoulder injury (a tear to his lat) that ended his season and required corrective surgery. The lefty threw 64 1/3 innings in 2014 until his season was cut short once again by injury in August.

Boone Whiting

In the early going of Whiting's minor-league career, he was known as a strike-throwing machine due to his lack of walks. The question was whether his stuff would allow him to miss enough bats and continue to pound the zone as he moved up the ladder. Oddly, Whiting has increased his K rate in each of his two seasons with Triple-A Memphis. But his walk rate has also gone up, to unacceptable levels. Whiting's profile has been turned on its head in the high minors.

Tyrell Jenkins (Former Cardinals Minor-Leaguer)

Former Cardinals prospect Tyrell Jenkins was potentially Rule 5 eligible this year. By trading Jenkins, the Cardinals didn't have to worry about protecting him from the Rule 5 draft by placing him on the 40-man roster. The Braves have placed Jenkins on their 40-man roster, making the righty ineligible for the draft.

Will the Cardinals make a selection in this year's Rule 5 draft?

It doesn't appear so. General manager John Mozeliak spoke with the media Wednesday night at the Winter Meetings. According to Jenifer Langosch of MLB.com, Mozeliak indicated that the Cards did not plan on making a selection in this year's Rule 5 draft:

GM John Mozeliak said there is a "low probability" that the #stlcards make a selection in tomorrow's Rule 5 Draft.

— Jenifer Langosch (@LangoschMLB) December 11, 2014