Every spring, teams from throughout Major League Baseball bring players to camp that are not part of the organization’s official 40-man roster. Known as non-roster invitees (NRIs), these players are often talented youngsters on their way to The Show, veteran Minor Leaguers looking for a breakthrough moment, or former Major Leaguers looking for a fresh start.

In all, 20 such players will head to Viera, Fla. with hopes of making it to Washington. That’s part of what makes their journey so special; should they impress the coaching staff, as Chad Tracy did in 2012, they could not only force their way onto the Opening Day roster but become household names on a championship-contending club.

Below is the final installment of our Spring Training Preview series: the non-roster invitees.

STARTING PITCHERS (4)

Bruce Billings

Right-hander Bruce Billings is a veteran of eight Minor League seasons and brings with him experience as a starter and reliever. He has accumulated a 65–61 record while posting a 4.08 ERA in 217 Minor League appearances (145 starts). Billings made his MLB debut with Colorado in 2011 and appeared in one game for the Yankees in 2014, striking out seven batters in four innings.

Mitch Lively

Mitch Lively signed with the Nationals organization in July of 2014, after making the transition from reliever to starting pitcher over the last two seasons. As a reliever, the 6-foot-5, 255-pound right-hander was 22–19 with 14 saves and a 3.76 ERA in 212 career Minor League appearances. In 42 career starts, he is 16–9 with a 4.10 ERA. Last season, Lively reported to Triple-A Syracuse where he went 5–2 with a 3.86 ERA in nine games/seven starts for the Chiefs.

Scott McGregor

A former St. Louis Cardinals farmhand, right-hander Scott McGregor joined the Nationals in June of 2014 and reported to Double-A Harrisburg before earning a promotion to Syracuse in August. He went a combined 3–3 with 4.64 ERA in 12 games/10 starts between the two levels.

Matt Purke

Matt Purke, the Nationals’ third-round selection in the 2011 First-Year Player Draft, appeared in eight games for Double-A Harrisburg before undergoing Tommy John ligament replacement surgery on his left elbow on May 28. The 6-foot-4 southpaw will enter his fourth camp as a member of the Nationals organization.

RELIEF PITCHERS (5)

Heath Bell

Veteran reliever Heath Bell joins the Nationals after a 2014 season in which he appeared in 13 games with the Tampa Bay Rays before stints with Triple-A Norfolk (Baltimore Orioles) and Triple-A Scranton/Wilkes-Barre (New York Yankees). The Nationals will be his eighth organization since signing with the Mets as an undrafted free agent in 1998. Bell was one of the premier closers in MLB from 2009–13, tallying 166 saves for three separate clubs, third most in MLB over that span. He appeared in three All-Star Games and took home the 2009 and 2010 NL Rolaids Relief Man of the Year.

Manny Delcarmen

Manny Delcarmen returns for his second season with the Nationals organization. He went 4–4 with four saves and a 3.13 ERA in 46 games out of the Triple-A Syracuse bullpen. Delcarmen struck out 8.2 batters per nine innings and improved his strikeout-to-walk ratio to 2.39, while surrendering just two home runs in 60.1 innings.

Eric Fornataro

Right-hander Eric Fornataro is a former St. Louis Cardinals farmhand who came to Washington on a waiver claim following the 2014 season. He began his professional career as a starter, but has transitioned to a relief role over the last three seasons. As a reliever, he is 9–12 with 21 saves and a 3.40 ERA in 141 Minor League appearances. Fornataro made his Major League debut in 2014, posting a 4.66 ERA in eight appearances for the Cardinals.

Rafael Martin

Rafael Martin advanced through three levels of Washington’s Minor League system in 2014, going 3–2 with 11 saves and a 1.39 ERA while striking out 66 batters and holding opposing hitters to a .171 batting average. He did not allow an earned run from May 16 to Aug. 17, a span of 46.1 innings over 29 games between Double-A Harrisburg and Triple-A Syracuse. His 11 saves were fourth among Nationals farmhands. Martin was named a MiLB.com Organization All-Star following the season.

Evan Meek

Evan Meek comes to Washington after spending the 2014 season with the Baltimore Orioles organization. The former All-Star (Pittsburgh Pirates, 2010) enjoyed five separate stints with the Orioles, going 0–4 with a 5.79 ERA in 23 appearances. He went 2–0 with 16 saves and a 1.94 ERA in 39 games for Triple-A Norfolk. His 16 saves were tied for seventh in the International League.

CATCHERS (3)

Spencer Kieboom

Former Clemson Tiger Spencer Kieboom is coming off his most productive season, bouncing back from 2013 “Tommy John” surgery by hitting .309 with 28 doubles, four triples, nine home runs and 61 RBI in 87 games for Single-A Hagerstown. He was named a South Atlantic League midseason All-Star and a MiLB.com Organization All-Star. Following the season, Kieboom hit .324 with two doubles, one home run, seven RBI and three runs scored for the Mesa Solar Sox of the Arizona Fall League.

Steven Lerud

Left-handed hitting catcher Steven Lerud comes to the Nationals after playing in 60 games for the Triple-A Gwinnett Braves, batted .250 with nine doubles, one triple, four home runs and 19 RBI. The former third-round pick of the Pittsburgh Pirates has spent time in five organizations, including the Philadelphia Phillies, with whom he briefly reached the Major Leagues in 2012 and 2013.

Pedro Severino

Pedro Severino is considered the best defensive catcher in the Nationals’ chain per Baseball America, and will enter the 2015 season rated as Washington’s top catching prospect and №13 prospect overall. The 21-year-old Bonao, Dominican Republic native advanced to Single-A Potomac for the first time in 2014, hitting .247 with 15 doubles, one triple, nine home runs and 36 RBI in 94 games.

INFIELDERS (7)

Emmanuel Burriss

Emmanuel Burriss, a Washington, D.C., native and graduate of Woodrow Wilson High School, returns for his second season with his hometown organization after spending the 2014 season with Triple-A Syracuse. He earned International League All-Star honors after hitting .300 with 18 doubles, seven triples, six homers, 46 RBI, 22 stolen bases and 80 runs scored. He ranked among IL hitters in runs scored (3rd, 80), triples (T-3rd, 7), batting average (T-7th, .300), and on-base percentage (9th, .377) while his .300 batting average was tied for fifth among Nationals farmhands.

Cutter Dykstra

A former second-round pick of the Milwaukee Brewers and the Nationals’ return in the Nyjer Morgan trade, Cutter Dykstra advanced to Double-A for the first time in his career in 2014. He was named an Eastern League mid-season All-Star after hitting .297 with 15 doubles, three triples, five home runs, 43 RBI, 10 stolen bases and 39 runs scored in the season’s first half.

Kila Ka’aihue

Kila Ka’aihue returns to the United States after spending the previous season-and-a-half with the Hiroshima Carp of Nippon Professional Baseball, where he hit .258 with 20 doubles, 25 home runs, 85 RBI, 77 walks and 56 runs scored in 156 games spanning the 2013 and 2014 seasons. He has appeared in 126 Major League games over parts of four seasons with Kansas City (2008–11) and Oakland (2012).

Clint Robinson

Left-handed power-hitting first baseman Clint Robinson, a former teammate of Ka’aihue in the Kansas City Royals system, joins the Nationals after spending last year in the Los Angeles Dodgers organization. Robinson, 30, is a career .300/.381/.510 hitter in 921 games spanning eight Minor League seasons, including a Texas League Triple Crown in 2010. He appeared in nine games for the Los Angeles Dodgers in 2014, going 3-for-9 with two RBI and three runs scored.

Matt Skole

Matt Skole returned to full strength in 2014 following 2013 Tommy John ligament replacement surgery, playing in 132 games for Double-A Harrisburg. He hit .241 with 29 doubles, one triple, 14 home runs, 68 RBI, 78 walks and 58 runs scored for the Senators. Skole ranked second in the Eastern league with 78 walks and was named an Organization All-Star by MiLB.com following the season.

Ian Stewart

A member of the Los Angeles Angels’ Opening Day roster in 2014, Ian Stewart played in 24 games before landing on the disabled list with a left-hand contusion. The power-hitting left-handed hitter has played parts of seven MLB seasons with three clubs, including Colorado (2007–11), Chicago-NL (2012) and Los Angeles (2014).

Dan Uggla

Dan Uggla joins the Nationals after spending the previous nine seasons with the Marlins (2006–10), Braves (2011–14) and Giants (2014). His 233 home runs as a second baseman lead all active players. Uggla, a three-time All-Star and 2010 Silver Slugger winner, is the only second baseman in Major League history to begin his career with six consecutive 20-plus home run seasons.

OUTFIELDERS (1)

Mike Carp

Mike Carp is a left-handed hitting slugger and versatile defender who has appeared in Major League games at first base (143 games/122 starts) and outfield (110 games/90 starts). In 2013, he set career marks in nearly every offensive category, starting 56 games for the World Series Champion Boston Red Sox. The former Mets draft pick has also played for the Seattle Mariners and Texas Rangers during his six seasons in the big leagues.

In 10 seasons in D.C., 76 players (Ray King and Pete Orr twice) have played in at least one game with the Nationals despite entering that same Spring Training as a non-roster invitee. 21 times players have earned spots on the Nationals’ Opening Day 25-man roster (designated by [OD]). A closer look:

2005 (7)2006 (12)2007 (11)2008 (10)2009 (11)2010 (7)INF Carlos BaergaLHP Micah BowieRHP Winston AbreuRHP Collin BalesterC Josh Bard [OD]RHP Miguel Batista [OD]RHP Hector CarrascoLHP Bill BrayLHP Mike BacsikLHP Michael HinckleyLHP Jesus ColomeC Jamie BurkeOF Jeffrey HammondsSS Royce Clayton [OD]1B/3B Tony BatistaLHP Ray King [OD]INF Alex CintronRHP Livan HernandezRHP Sun-woo KimOF Alex Escobar2B Ronnie Belliard [OD]LHP Charlie ManningLHP Wil Ledezma [OD]RHP Joel PeraltaC Keith OsikC Wiki GonzalezRHP Jesus Colome [OD]LHP Mike O’ConnorRHP J.D. MartinRHP Drew StorenINF Rick ShortRHP Kevin GryboskiC/1B Robert Fick [OD]INF Pete OrrINF Pete OrrRHP Willy Taveras [OD]OF Brandon WatsonC Brandon HarperINF D’Angelo JimenezLHP Odalis Perez [OD]OF Jorge PadillaOF George LombardLHP Ray King [OD]RHP Brian SanchesOF Corey PattersonRHP Santiago RamirezLHP Arnie MunozRHP Steven ShellRHP Jorge SosaRHP Saul RiveraRHP Jason SimontacchiC Wil NievesRHP Julian Tavarez [OD]OF Mike Vento1B Dmitri Young [OD]RHP Jordan Zimmermann1B Daryle Ward [OD]2011 (6)2012 (7)2013 (4)2014 (1)2015 (TBD)INF Brian BixlerOF Rick AnkielLHP Fernando AbadRHP Blake TreinenINF Alex Cora [OD]OF Corey BrownRHP Ross OhlendorfRHP Chad Gaudin [OD]OF Brett Carroll [OD]RHP Tanner RoarkRHP Ryan MattheusC Sandy LeonINF Zach WaltersOF Laynce Nix [OD]C Carlos Maldonado1B/OF Matt Stairs [OD]1B/OF Xavier Nady [OD]1B/3B Chad Tracy [OD]