System Rankings: 21 and younger (30-21)

With Spring Training underway and the 2017 season rapidly approaching, MiLB.com looks at the state of all 30 farm systems and ranks them, according to certain changing criteria with each edition. This week, we focus on prospects who will be 21 or under on Opening Day and consider the quality and quantity of top talent in each system. The 30-21 rankings:

 30. Arizona Diamondbacks

Young talent takes center stage in Arizona as two of the system's top three prospects are under the age of 22: Domingo Leyba and Jasrado Chisholm. The switch-hitting Leyba has shown versatility in the field, where he's played both shortstop and second base, and has the chance to hit for a decent average. The D-backs selected outfielder  Anfernee Grier with the 39th overall pick in last year's Draft, and while he was marred by shoulder soreness in his pro debut, he should be ready to go this sesaon. After signing with Arizona four years ago at the age of 16, Sergio Alcántara has had to overcome injuries, but with a 70-grade arm and plus defense, the D-backs hope the 20-year-old shortstop is worth the wait. 

 29. Kansas City Royals

The Royals got a boost at last year's Draft with the selections of right-hander A.J. Puckett and outfielder Khalil Lee, who ranked second in the Arizona League with 33 walks as a 17-year-old. After a brief stint in the AZL, Puckett shined with five hitless innings for Class A Lexington on Aug. 21. Meibrys Viloria, who turned 20 in February, broke out in his third pro season by leading the Pioneer League with a .376 average and 55 RBIs. He went on to earn MVP honors. Like the D-backs, the Royals do not have a top-100 prospect in their system, which hurts them here, but there's still plenty of time for their youngsters to develop.

 28. Baltimore Orioles

The youngest birds proved to be the most successful last year as Class A Short Season Aberdeen was the only O's affiliate to post a winning record. The IronBirds were led offensively by third-round pick Austin Hays, who hit .336 in his pro debut, while top pitching prospect Cody Sedlock notched a 3.00 ERA over 27 innings in nine starts. The first-round pick held New York-Penn League foes to a .158 batting average. With Chance Sisco and Hunter Harvey turning 22 in recent months, the O's aren't as high on this list as they could've been.

 27. San Francisco Giants

Christian Arroyo, MLB.com's No. 89 overall prospect and the club's top position player, saw a dip in his numbers as he adjusted to the Eastern League last season, but he led Double-A Richmond with 130 hits and 35 doubles. Patrolling the outfield, 2016 third-round pick Heath Quinn quickly made an impact at the lower levels. Across Rookie, short-season and Class A Advanced ball, the 21-year-old batted .344 with nine homers and 34 RBIs in 60 games. Sandro Fabian, a 19-year-old outfielder from the Dominican Republic, hit .340 in the Arizona League and could be looking at a full-season debut in 2017. What the system lacks is young pitching; none of the club's top 30 prospects are pitchers who fit the under-22 guideline of these rankings.

 26. Los Angeles Angels

While the Angels have had some down years recently, they have plenty of emerging young talent, starting with their top three prospects: Jahmai Jones, Matt Thaiss and Brandon Marsh. As an 18-year-old, Jones was regarded as a mature leader last season with Rookie-level Orem before making his way to Class A Burlington. After improving in his sophomore campaign with a. 302 composite average, he leapfrogged Thaiss -- who hit .292 in his pro debut -- on the team list. Marsh was selected in the second round last June but has yet to play due to a back issue that the Angels have approached cautiously.

 25. Detroit Tigers

The Tigers system is topped by a pair of recent first-round picks: right-handers Matt Manning and Beau Burrows. After being selected ninth overall in 2016, the 18-year-old Manning posted a 3.99 ERA over 29 1/3 innings in the Rookie-level Gulf Coast League. Burrows, taken 22nd overall in 2015, has a 2.81 career ERA over 125 frames in Rookie ball and Class A. Fans in Motown also can look forward to outfielder Derek Hill's 70-grade speed and right-hander Gerson Moreno's 70-grade fastball -- both prospects are 21.

 24. Miami Marlins

Fish fans have had to be patient, since the club's top two prospects were unable to pitch in 2016. Braxton Garrett, who at No. 43 overall is the highest ranked prospect in this group of teams, was drafted seventh overall last June but did not sign until mid-July, keeping him from making his Minor League debut last summer. Taken second overall in 2014, Tyler Kolek had a rough start to his career, both statistically and injury-wise -- Tommy John surgery cost him the entire 2016 campaign. Along with those two, the Marlins have six players under the age of 22 rounding out their top 10 prospects.

 23. St. Louis Cardinals

Last season, Cardinals fans got a glimpse at some of their best pitching prospects in Alex Reyes and Luke Weaver, and there's still plenty of exciting arms in the pipeline. Right-handers Sandy Alcantara, 21, and Junior Fernandez (shown above), 19, both boast above-average fastballs and garnered midseason promotions to the Florida State League in 2016. On the basepaths, 18-year-old Delvin Perez -- MLB.com's No. 91 overall prospect -- stole 12 bags in 13 tries for the GCL Cardinals and has plus tools on defense at shortstop, while shortstop Edmundo Sosa is also solid defensively with above-average speed.

 22. Minnesota Twins

The attention the Twins system garners these days focuses on a pair of first-round picks from the last three Drafts. Shortstop Nick Gordon -- the fifth overall pick in 2014 and MLB.com's No. 50 prospect, posted a career-best .721 OPS in the pitcher-friendly Florida State League last year. After being selected 15th overall last June, Alex Kirilloff batted .306 for Rookie-level Elizabethton, but his sophomore season will have to wait as the 19-year-old right fielder needs Tommy John surgery.

 21. Texas Rangers

Like the Marlins, the Rangers also boast six top 10 prospects who are 21 or younger, highlighted by Leody Taveras, MLB.com's No. 55 overall prospect who hit .271 in 73 games for Spokane as a 17-year-old. Hurlers Ariel Jurado and Brett Martin, both 21 and both 2016 Draft picks, round out Texas' top 10. First-rounder Cole Ragans and second-rounder Alex Speas began their careers in the Rookie-level Arizona League. While the former had 7 2/3 tough innings over four outings, the latter posted 8 1/3 scoreless frames in four appearances. Rangers fans also can look toward 20-year-old Eric Jenkins who showed off his 70-grade speed with 51 stolen bases in his first full season to lead the organization.