If a player signs a professional contract when he is 19 years or older, he becomes Rule 5 eligible four years later. That means that players who signed in or before 2007 and were at least 19 years old at the time are at risk to be lost in December if not on the 40-man roster.
If a player is 18 years old or younger when he signs, he doesn't become eligible for the Rule 5 Draft for five years. In other words, players drafted out of high school in 2006 are eligible for the first time this offseason.
Any eligible player left off the 40-man roster can be nabbed during the Rule 5 Draft for a cost of $50,000. That player then has to stick on the claiming team's Major League roster for the entire 2011 season or else be offered back for half of the selection price.
Here is a look at some of the Pirates' Minor League players who are Rule 5 eligible and the likelihood that each will be protected:
Near certain additions: Jeff Locke
Locke, who was acquired along with Charlie Morton and Gorkys Hernandez for Nate McLouth, emerged as one of the organization's most promising left-handers in 2010. After posting a 3.54 ERA in 17 starts with high-A Bradenton (Fla.), Locke had a 3.59 ERA in 10 outings with Altoona to end the year. He limited opponents to a .251 batting average during the season and maintained a dominant strikeout-to-walk ratio (139-to-26).
Up for debate: Daniel Moskos, Nathan Adcock, Brian Friday, Tony Watson
Each one of these players could make a case to be protected, though the decision doesn't appear to be as cut-and-dry as the group listed above.
Moskos is an interesting case, given that he dominated Double-A hitters, only to then have limited success when moved up to Triple-A midseason. The No. 4 overall pick in the '07 First-Year Player Draft, Moskos is no longer viewed as a potential starter, so the Pirates are trying to see if he can find a fit in the bullpen. He had a decent strikeout-to-walk ratio and limited hitters to a .179 batting average in 37 appearances with Altoona. But control issues and the feeling that Moskos was slow to make adjustments in Triple-A led to the left-hander being sent down in August.
Acquired from the Mariners in 2009, Adcock is a right-handed starter who put up some intriguing numbers with Bradenton this year. He finished with 113 strikeouts and a 3.38 ERA in a career-high 141 1/3 innings. Adcock had fairly equal success against both right-handed and left-handed hitters and showed few control issues. What the Pirates have to determine is whether they think Adcock would be able to stick on a big league roster all of next season. If so, they'll protect him.
Neither Friday, nor Watson, have panned out to be top prospects, even though both were taken early in the '07 Draft. Still, each has some degree of value and could be snatched if not protected. Watson, who made nine starts and 25 relief appearances for Altoona in 2010, dominated left-handed hitters, limiting them to a .131 batting average.
Friday spent most of last season with Indianapolis, where he played both middle infield positions. As the Pirates look to find potential future middle infielders, Friday could be in that mix.
Notable '07 Draft picks likely to be left off: Duke Welker, Andrew Walker
The Pirates made Welker their second pick of that Draft class. Walker wasn't far behind, either, as he was taken in the fifth round. Welker began his third full season in the Minors only at the low-A level, though he was promoted to high-A during the year. The Pirates transitioned Welker into a full-time relief role in 2010.
Like Welker, Walker's climb through the system has been slow. He spent last year with Bradenton and got few at-bats playing behind catchers Tony Sanchez and Eric Fryer. In 66 at-bats, Walker finished with only six hits.
Unlikely to be protected ... again: Michael Crotta, Michael Dubee, Jim Negrych, Miles Durham
These are just four of the players who were not protected in the 2009 Rule 5 Draft, and they are likely to remain off the 40-man roster again this year. None of the Pirates' players left unprotected last year were taken.