Pedro Ciriaco, SS: Already viewed as the organization's top defensive infielder, Ciriaco returned to Class A Advanced Visalia for a second go-round in 2008 and his offense finally clicked as well. After hitting .251 with 20 steals there in '07, the 23-year-old batted .310 with five home runs, 61 RBIs and 40 steals for the Oaks. A California League All-Star, he led the system in steals and finished seventh in average. He boasts a .275 career average over six seasons, the first three being short-season campaigns, and he continues to show new life in his bat with a career-best 26 doubles.

Spotlight on the D-backs An up-close look at the club as we approach Opening Day News and Features • Rotation to lead • Melvin Q&A • Organization report • Prospects to watch • Quick hits Multimedia • Josh Byrnes • Upton • Webb • Haren • Drew • Eric Byrnes

More team spotlights: American ¬ Angels Athletics Blue Jays Indians Mariners -- March 29 Orioles Rangers Rays Red Sox Royals Tigers Twins White Sox Yankees National ¬ Astros Braves Brewers Cardinals Cubs D-backs Dodgers Giants Marlins Mets Nationals Padres Phillies Pirates Reds Rockies

Collin Cowgill, OF: Don't let the Kentucky product's 5-foot-9 status fool you. He's emerged in only a few months since being the Diamondbacks' fifth-round pick as possibly their top power prospect. At age 22, after missing his junior year due to a broken hamate bone, he burst out of the gate as a pro with 11 homers in just 20 games at short-season Yakima, hitting .304 with 28 RBIs and five steals. He moved up briefly to Class A South Bend, where he hit .249 with 17 RBIs. Cowgill has a quick bat and is a fine outfielder.

Kevin Eichhorn, RHP: The bloodlines certainly will show in the future for the son of Mark Eichhorn, who pitched in the big leagues for more than a decade. The 19-year-old, a 2008 third-round pick out of high school in California, is a terrific athlete who was also a star shortstop in high school. He throws a fastball around 90 to go with a curveball and changeup and is working on consistency and reps. He made a brief pro debut with 2 2/3 innings at Rookie-level Missoula.

Mark Hallberg, SS/2B: If the talented high school kids taken recently by the Diamondbacks may need some time to blossom, this 2007 ninth-rounder out of Florida State could shoot right through the system, thanks to his all-around game, versatility, work ethic and savvy. The 23-year-old has great plate discipline and is a smart player who hit .283 with 29 RBIs at Visalia. After missing the first half of the season due to a thumb injury, he drew 30 walks and struck out only 28 times in 272 at-bats. Hallberg won MVP honors in his makeup time in Hawaii Winter Baseball after hitting .362.

Wade Miley, LHP: Another good southpaw coming up is this Southeastern Louisiana product taken with a supplemental first-round pick last year. He posted a 4.91 ERA in seven games at short-season Yakima, striking out 11 in as many innings. His breaking stuff is his bread and butter, highlighted by a slurvy offering. The 22-year-old also throws a fastball in the low-90s and a changeup and continues to work on command.

Reynaldo Navarro, SS: The 19-year-old was a third-round pick in 2007 out of high school in Puerto Rico. A switch-hitter with great tools, his best may be his speed. Navarro has a little power, but it's not his game per se. Look for him to make his full-season debut this spring at South Bend after hitting .258 with two homers, 31 RBIs and 17 steals at Missoula.

Jarrod Parker, RHP: After signing at the deadline as the ninth overall pick in 2007, Parker made his pro debut last summer at South Bend, just two hours down the highway from his Indiana home, making for a nice built-in fan base with the Silver Hawks. And he did those fans proud, going 12-5 with a 3.44 ERA and 117 strikeouts in 117 2/3 innings while walking only 33. He tied for third in the system in wins and was fourth in ERA. He has perhaps the best fastball in the system as well as a great slider and is rounding out a four-pitch arsenal with a curve and changeup. The Diamondbacks love his feel for pitching and feel the sky is the limit for the 20-year-old.

Gerardo Parra, OF: The top hitting prospect in the system, Parra has stolen at least 20 bases in each of his three pro seasons and comes off a World Baseball Classic in which he nabbed an outfield slot for Venezuela. After winning the Midwest League batting crown with a .320 average in 2007, he batted .286 between Visalia and Mobile in 2008 and tied for third in the organization with 28 steals. His reliable bat and great defensive ability could see the left-handed batter continue to progress quickly, despite the fact he's only 21.

Daniel Schlereth, LHP: The Diamondbacks were thrilled to see the hard-throwing closer prospect out of Arizona still on the board with the 26th pick, and he could be a quick mover. The son of former NFL star and current ESPN commentator Mark Schlereth made a brief pro debut with three appearances at Missoula, then posted a 2.00 ERA over nine innings at South Bend. With a fastball in the mid-90s offset by a power curve, he's got what it takes to close right now. He posted a 1.81 ERA in 34 relief appearances for the University of Arizona before the draft.

Cesar Valdez, RHP: While Jarrod Parker may be the system's top starting pitching prospect, it was the 23-year-old Valdez who was named the Diamondbacks' 2008 Minor League Pitcher of the Year. Signed out of the Dominican Republic in 2005, the 23-year-old went 13-8 with a 3.14 ERA and 140 strikeouts -- second in the system -- between Visalia and Mobile. He was 10-3 with a 2.53 ERA for the Oaks, dominating with a curveball and changeup that are both regarded as tops in the organization. His command has steadily improved and he was added to the 40-man roster over the winter.