PHOENIX -- Prospects who are invited to Major League camp usually fall into one of two categories -- either they're competing for a spot on the team, or they're gaining the valuable experience of being in a big league clubhouse, while making an impression for a future callup.
Part three of the D-backs' Spring Training preview takes a look at some of the prospects to watch this spring. Note this is not a ranking of prospects, nor is it intended to separate prospects from non-prospects. It is just a sampling of guys to keep an eye on this spring.
• Comeback candidates | Newcomers
RHP Archie Bradley: This is a big spring and an important season for the 23-year-old, who was a first-round pick (seventh overall) in 2011 and the No. 1 prospect in the system in 2015, according to MLBPipeline.com. He won a spot in the rotation last spring and started out well, before he got hit in the face with a line drive, sending his season in a tailspin. He'll have a chance to win a spot in the rotation this spring.
RHP Braden Shipley (No. 2): The team's first-round pick in 2013 will likely begin the year in the Minors, but for the second straight year he will get the opportunity to show big league coaches what he can do during Spring Training. Shipley, who spent last year in Double-A Mobile, certainly has a chance to pitch in the Majors this year.
OF Socrates Brito (14): Brito is a good example of making the most of a spring in big league camp. While he did not have a realistic chance to make the team, he played well enough during the spring to open eyes and that earned him a late-season promotion to the big leagues. He will compete for a spot in the outfield this time around.

INF Brandon Drury (5): Drury made his Major League debut in September, after impressing during big league camp. He is in the mix at third base and second this spring, and while he likely will begin the year in the Minors, a strong showing with the bat this spring could change that.
RHP Yoan Lopez (3): Signed out of Cuba last year, Lopez's 2015 season was a disappointment. He struggled on the field and reportedly left his Minor League team at one point, prompting questions about his attitude. The D-backs paid a lot of money to sign him and would like to see him take a step forward both on and off the field this year.
C Peter O'Brien (7): O'Brien wowed last spring with his batting-practice sessions, but had some throwing issues behind the plate and was moved to the outfield for most of the year at Triple-A Reno. The plan when the 2015 season ended was to move him back behind the plate.

RHP Tyler Wagner (10): Wagner came over from the Brewers along with Jean Segura in a trade last month. He will be in the mix for a rotation spot this spring, and if he doesn't make the team, he will be someone they keep an eye on should an opening come up during the season.
RHP Jake Barrett (17) and Enrique Burgos (NR): These two are grouped together because they are both hard-throwing right-handed relievers who will compete for bullpen jobs this spring. Burgos made his Major League debut last year and the team thinks Barrett could be a future closer.