Your fantasy baseball rankings look a little stale. KFFL.com's Fantasy Baseball Player Prospecting series highlights the exploits of minor league baseball players, including top MLB prospects. Find out who'll make an impact, whether it's in your rotisserie or head-to-head baseball game next week or in your fantasy baseball keeper league two years from now.

Ever since he was taken in the 16th round of the 2007 out of Division II Southern Indiana, Minnesota Twins rookie OF Darin Mastroianni has been considered a fringe prospect and a fringe major league player at best. The 5-foot-11, 190-pound center fielder is a scrappy player who makes light contact, grinds out long at-bats, works the count for walks and uses his wheels to his advantage on both the base paths and on defense.

Limited upside aside, Mastroianni has been called up by an organization that will value his strengths and give him the best chance to be a fantasy baseball contributor. Even though the Twins are dead last in the American League in runs scored (104), manager Ron Gardenhire's approach to generating more offense hasn't been conservative Earl Weaver baseball, but putting a stronger emphasis on executing small ball maneuvers.

If BABIP works in his favor, the 26-year-old Mastroianni could shine in Gardenhire's small-ball world.

Last night on his first night with the club, Mastroianni started in left, batting eighth, and went 0-for-3 in the Twins' 6-2 loss to Toronto.

Prior to his call-up, the 26-year-old hit .346 with no homers, 11 RBIs, 10 runs scored and had 10 steals in 11 tries with Triple-A Rochester.

As shown by his .279 career batting average and .371 slugging percentage, Mastroianni doesn't make consistent hard contact and his success is dependent on how the BABIP pendulum swings.

The good news, Mastroianni has been able to find a way to reach base at a healthy rate (.368 on-base percentage), and he has been an aggressive and efficient base stealer who has averaged 40 steals a season from 2007-2011.

If luck works in his favor, Mastroianni has the ability to duplicate Chicago Cubs outfielder Tony Campana's success in the American League.

If one's AL-only team is in need of speed, Mastroianni is worth a flier.

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To help a bullpen whose depth has been hit hard by injuries, the Philadelphia Phillies called up hard throwing southpaw Jake Diekman from Triple-A Lehigh Valley.

In 15 1/3 innings with Lehigh Valley, Diekman was dominant versus International League opponents, posting a 1-0 record, a 0.59 ERA, five saves and a 22:3 strikeout-to-walk ratio.

A converted starter, Diekman has blossomed in the relief role, featuring a low- to mid-90s fastball with late movement and a sweeping breaking ball in the high 70s.

In a bullpen anchored by Jonathan Papelbon and Antonio Bastardo, Diekman will not make much of a fantasy impact anytime soon, but he's a high-end arm to watch that is gradually getting better.

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The inability to develop homegrown pitching has been a pitfall for the Pittsburgh Pirates' organization over the last two decades, but 2013 is looking rosier for pitching-starved Bucs fans with the expected arrival of potential aces Gerrit Cole and Jameson Taillon.

Taillon, the second overall pick of the 2010 draft, is making a strong case that he could be the minors' top pitching prospect above low Single-A ball, where Baltimore's Dylan Bundy resides.

In high Single-A Bradenton's 16-3 win over Clearwater, Tallion picked up the win after firing six scoreless innings of three-hit ball. He walked one and struck out three.

In 36 2/3 innings with Bradenton, the 6-foot-6 Texan is 2-2, with a 1.47 ERA and a 36:7 strikeout-to-walk ratio. Taillon has yet to allow a home run this year after surrendering nine round-trippers in 2011.

Taillon, a Grade A talent, features two top-notch pitches in a mid- to high-90s fastball and a wicked 12-to-6 curveball. His slider earns high praise, and he is also working on a changeup.

Taillon is on pace for a summer promotion to Double-A Erie.