Major League regulations stipulate that any player who signed his first professional contract before age 19 and has been in the organization for five seasons, or who signed after age 19 and has been in the organization for four seasons, is eligible to be selected in the Rule 5 Draft if he's not on the 40-man roster. Thus, players such as Matz must be protected, while more recently drafted prospects such as Brandon Nimmo and Gavin Cecchini are safe.
If selected, a player must remain on his new team's active roster or disabled list all season, or be offered back to his original club for half of the original $50,000 selection fee. The Mets made one selection in last year's Rule 5 Draft, plucking left-hander Kyle Lobstein from the Rays and immediately flipping him to the Tigers for cash.
The Mets' protection decisions were less obvious this year than last November, when they added Zack Wheeler and five others to the 40-man roster. Four of those six wound up appearing in the Majors.
Matz, a second-round selection and the Mets' first pick in the 2009 First-Year Player Draft, did not make his professional debut until '12 due to left elbow issues that led to Tommy John surgery. He dominated down the stretch that season, however, and picked up where he left off with a 2.62 ERA, 121 strikeouts and 38 walks in 106 1/3 innings this year for Class A Savannah. He later tacked on 12 2/3 shutout innings with 17 strikeouts and two walks in the South Atlantic League playoffs.
The Stony Brook, N.Y., native is still only 22 years old and could rise rapidly up the Minor League ranks this summer, provided he can stay healthy.
deGrom, 25, nearly earned a September callup after going 7-7 with a 4.51 ERA over three Minor League levels, advancing from Class A St. Lucie all the way to Triple-A Las Vegas. The Mets' 19th-ranked prospect, deGrom could compete for a rotation spot as soon as this spring.
Walters, 26, led the Minor Leagues with 38 saves, five more than the next-closest pitcher. He accumulated all of them at Double-A Binghamton, posting a 2.09 ERA in 56 innings while priming himself for a big league debut at some point in 2014.
Goeddel, 24, went 9-7 with a 4.37 ERA in 25 starts for Binghamton, striking out 125 batters with 58 walks in 134 innings. He could open next season as high as at Las Vegas, potentially alongside blue-chip prospects Noah Syndergaard and Rafael Montero at the top of the rotation.
Some of the higher-profile players the Mets left unprotected are left-hander Chase Huchingson, who is currently serving a 50-game suspension for a second violation of Minor League Baseball's drug policy, and outfielder Cory Vaughn, who batted .252 with 10 homers over three levels this season.
The Mets' 40-man roster now stands at 40, meaning they will need to make cuts once they begin acquiring free agents. Infielder Jordany Valdespin and reliever Scott Atchison are among the Mets who could be at risk.