PHOENIX -- Brandon Moss hit 21 home runs in 84 games last year. Evan Scribner's three scoreless innings in the middle of Game 162 helped unseat the Rangers and make American League West champions out of the A's. Jim Miller was just as much of a cog out of the bullpen on numerous occasions.
And yet none of these three players were on the Opening Day roster. In fact, each entered camp on the non-roster list.
This year, that list includes 19 players, many of whom will simply help fill out the Triple-A Sacramento roster. Others, like Moss, Scribner and Miller proved to be, could potentially result in unexpected gems. That's why, over the next several weeks, close watch will be kept on these players to see if any of them can earn a trip to Oakland this year:
RHP Bruce Billings: The A's plucked him from the Rockies in exchange for fan-favorite Mark Ellis in 2011. Billings made just a handful of big league appearances that season, and he has spent the rest of his six-year professional career in the Minors, where he's logged a 3.86 ERA in 168 games (103 starts).
The right-hander was quietly the workhorse of Sacramento's staff in 2012, while posting a 3.98 ERA in 133 1/3 innings as a starter. He figures to be near the top of the list for a promotion this season should an injury hit the A's staff.
RHP Mike Ekstrom: The A's went after the 29-year-old early this offseason, and it's easy to see why when looking at the reliever's 2012 numbers. He was 3-1 with a 2.53 ERA in 57 innings for Triple-A Colorado Springs, fanning 57 and walking just 18 while never allowing a home run -- and that was while pitching his home games in a hitters' park.
It's unlikely Ekstrom squeaks his way onto the roster when camp breaks, just because the A's bullpen is already overcrowded, but should he produce quality numbers at Sacramento, the righty could find himself on the same path traversed by Miller and Scribner last year.
RHP Brian Gordon: Gordon trumps all others on this list with the most professional experience, having been in the game since 1997, when he was drafted in the seventh round by the D-backs as an outfielder. Ten years later, he made the transition to the mound, and he has since compiled a 3.05 ERA with 321 strikeouts and 86 walks in 371 2/3 innings between the Double-A and Triple-A levels.
The 34-year-old, back in the United States after pitching in Korea since the middle of 2011, can pitch as a starter or reliever. He's made just five career Major League appearances, but provides the organization with decent depth and veteran leadership for a young pitching staff in Sacramento.
RHP Kyler Newby: The 27-year-old is entering his ninth season of professional baseball, having spent the first seven with Arizona and the last year with Baltimore -- much of it at the Double-A level, with brief stints at Triple-A along the way.
Newby spent the majority of the 2012 season at Double-A Bowie, where he was 5-4 with 19 saves and a 2.44 ERA in 42 relief appearances. He's also started in his career, and has averaged 10.06 strikeouts per nine innings in 261 Minor League outings.
LHP Hideki Okajima: The 37-year-old perhaps has the best shot of any pitchers on this list to make the team out of Spring Training, as he has experience on his side. Before suiting up for the Fukuoka SoftBank Hawks of the Japan Pacific League last year, Okajima pitched five seasons with the Red Sox, compiling a 3.11 ERA in 261 outings, along with a 2.11 ERA in 17 postseason appearances.
LHP Garrett Olson: A former first-round Draft pick by the Orioles in 2005, Olson has struggled with consistency in nearly every Major League stint, posting a 6.26 ERA in 104 appearances -- including 44 starts -- while playing for the O's, Mariners, Pirates and Mets.
The A's have yet to decide what role suits Olson best for them, but he provides further depth in Triple-A and could warrant a promotion in the middle of the summer when the A's will likely need an arm.
LHP Justin Thomas: Taken in the fourth round by the Mariners in the 2005 Draft, Thomas has bounced around to the Pirates, Red Sox and Yankees, making a few relief appearances with each team along the way.
Thomas' career 6.93 ERA isn't pretty, but the A's believe with improved control, he can be an important bullpen piece. At least at the start of the season, he'll be one in Sacramento.
C Luke Montz: The power hitter spent seven seasons in the Nationals organization before stints with the Mets and Marlins. Over the past two seasons, split between Double-A and Triple-A, he's totaled 51 home runs and 152 RBIs in 241 games. That type of power is attractive to the A's, who see him as their third best catching option this spring, behind Derek Norris and John Jaso.
INF Scott Moore: The 29-year-old brings versatility to an already crowded A's infield, much like Adam Rosales. He played in 72 games for Houston last year, spending time at third base, first base, second base, right field and left field. A career .242 hitter with 16 home runs and 53 RBIs in 152 games, Moore has a chance to earn time in a utility role with Oakland this summer should injuries force the A's to reach into their depth pool.
Up and coming: Joining these players on Oakland's non-roster list are injured right-hander Andrew Carignan (Tommy John surgery) and a handful of prospects, including right-hander Sonny Gray; catchers David Freitas, Ryan Ortiz and Beau Taylor; infielders Miles Head, Jefry Marte, Darwin Perez and Addison Russell; and outfielder Michael Choice.
Jane Lee is a reporter for MLB.com. Read her blog, Major Lee-ague, and follow her on Twitter @JaneMLB.