While Gattis will come to camp with the hope of landing a spot on the Opening Day roster as a backup catcher or outfielder, Gilmartin, Wood and Graham will have the opportunity to prove why they are some of the top pitching prospects in the Braves' system.
This year's other notable non-roster invitees include slick-fielding shortstop Nick Ahmed, veteran infielder Blake DeWitt and outfielder Todd Cunningham.
Interestingly, Joe Terdoslavich is listed with Cunningham and Jordan Parraz as this year's non-roster outfielders. Terdoslavich was viewed as Chipper Jones' potential replacement when he came to his first big league Spring Training last year. But his defensive struggles led him to spend a majority of last year as Double-A Mississippi's first baseman.
Gattis will arrive at Spring Training looking to build on the success he created while spending the past few months in the Venezuelan Winter League. The 26-year-old catcher hit .303 with 16 home runs and a .595 slugging percentage in 53 games with Zulia.
Gattis' success in Venezuela added to the confidence he gained while combining to hit .305 with 18 home runs and a .995 OPS in 74 Minor League games last year. His numbers might have been even more impressive had he not injured his left wrist soon after being promoted from Class A Advanced Lynchburg to Double-A Mississippi.
With the potential that Brian McCann could miss most of April while recovering from shoulder surgery, Gattis could begin the season as Atlanta's backup catcher. If he proves that he can hit big league pitching, the Braves could also decide to give Gattis some time in left field.
DeWitt appears to be another non-roster invitee with some hope to gain a spot on the Opening Day roster. The 27-year-old infielder has played more than 400 Major League games with the Cubs and Dodgers. He has the ability to play second base, third base and either of the corner outfield spots.
This will be the first big league camp for Graham, who has been considered by some scouts to be the organization's top pitching prospect. The 22-year-old right-hander combined to go 12-2 with a 2.80 ERA in 148 innings with Lynchburg and Mississippi last season.
The Braves took Wood with their second-round Draft pick in June and then watched him go 4-3 with a 2.22 ERA in 13 starts with Class A Rome. Wood, a hard-throwing 21-year-old left-hander from the University of Georgia, recorded 52 strikeouts and issued 14 walks in 52 innings.
Gilmartin, the Braves' top selection in the '11 Draft, impressed with the poise he displayed during his first big league camp last year. The polished 22-year-old left-hander then compiled a 3.84 ERA in 27 combined starts with Mississippi and Triple-A Gwinnett.
Ahmed's stock appeared to rise as he displayed his solid defensive skills in the 2012 Arizona Fall League. A hard-nosed shortstop who has been compared to Jeff Blauser, Ahmed hit .269 and recorded 40 stolen bases while spending the 2012 season with Lynchburg.
Cunningham spent last summer displaying some of the hitting skills the Braves projected when they took him in the second round of the '10 Draft. While hitting .309 with a .767 OPS in 120 games with Mississippi, he also created confidence that has enough range to play any of the three outfield positions.
Below is a list of all of this year's non-roster invitees:
Pitchers (9): LHP Ryan Buchter, LHP Yohan Flande, Gilmartin, Graham, LHP Dusty Hughes, RHP Wirfin Obispo, LHP Daniel Rodriguez, RHP Gus Schlosser, Wood
Catchers (6): Luis De La Cruz, Gattis, Matt Kennelly, Matt Pagnozzi, Braeden Schlehuber, Jose Yepez
Infielders (3): Ahmed, DeWitt, Joe Leonard
Outfielders (3): Cunningham, Terdoslavich, Parraz
Mark Bowman is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.