As an accompaniment to our Top 20 Rookies list, we're taking an in-depth look at rookie candidates for every club. In this installment, it's the American League clubs, highlighting those with the most real-life and the most fantasy impact potential. If you missed yesterday, click to read our National League Rookie Preview.

• Rookies: Players who have reached the major leagues but still have rookie eligibility.
• No MLB Experience: Players on the 40-man roster who have not reached the major leagues. A single asterisk (*) denotes a player added to the 40-man last offseason, while a double asterisk (**) signifies a Rule 5 draft pick.
• Who You Calling Rookie?: Players who appear in the 2013 Prospect Handbook yet are not eligible for the Rookie of the Year balloting because they have too much major league service time. Not every team has a player in this category.
• On The Horizon: Players who were on a Top 10 Prospects list but are not yet on a 40-man roster, yet have sufficient experience (200 plate appearances or 200 batters faced at Double-A or higher) to forecast at least a cup of coffee in 2013.

We also identify each team's top rookie—right out of the Prospect Handbook—and the rookie with most potential for fantasy impact in 2013. Bear in mind that with few exceptions, such as Mike Trout and Bryce Harper last year, rookies are poor percentage plays in fantasy sports. That's why we recommend most rookies only in keeper or deep single-league formats.

BALTIMORE ORIOLES

Rookies (6)
RHP Dylan Bundy, RHP Steve Johnson, C Luis Exposito, OF Xavier Avery, OF Russ Canzler, OF L.J. Hoes
No MLB Experience (5)
LHP Mike Belfiore*, RHP Zach Clark*, LHP T.J. McFarland**, LHP Tsuyoshi Wada, 2B Jonathan Schoop*
On The Horizon
RHP Mike Wright

Top Rookie: Steve Johnson laid claim to a big league job for 2013 by going 4-0, 2.11 in 12 appearances with Baltimore last year.

Fantasy Impact: The Orioles signed Dylan Bundy to a major league contract out of the draft, so even with his youth he's on an accelerated timetable to Baltimore. A month or two in Double-A and he could be ready to join the big league rotation, where his athleticism and precociousness could rival the 20-year-old version of Zack Greinke. (Leagues: prime keeper target) [...] Continue Reading »

The annual American League and National League media guides, the so-called Red (AL) and Green (NL) books, offer a wealth of contemporary and historical information on all 30 major league clubs: 2012 league leaders, comprehensive managerial registers dating back to the Deadball Era, and listings for all-time league category leaders and award winners, to name just a few.

Of the greatest interest to BA readers of the Red and Green books, however, is the inclusion of each organization's official list of rookies for 2013. This takes the guesswork out of service-time considerations, particularly for relievers, who can log weeks of big league time while making few appearances. The Red and Green books even include an official definition for rookie qualifications (which we have conveniently included at the bottom of this post).

So as an accompaniment to our Top 20 Rookies list, let's take a closer look at rookie candidates for every National League club (we'll do the American League tomorrow). We've broken each club's rookie candidates into one of four groups:

• Rookies: Players who have reached the major leagues but still have rookie eligibility.
• No MLB Experience: Players on the 40-man roster who have not reached the major leagues. A single asterisk (*) denotes a player added to the 40-man last offseason, while a double asterisk (**) signifies a Rule 5 draft pick.
• Who You Calling Rookie?: Players who appear in the 2013 Prospect Handbook yet are not eligible for the Rookie of the Year balloting because they have too much major league service time. Not every team has a player in this category.
• On The Horizon: Players who were on a Top 10 Prospects list but are not yet on a 40-man roster, yet have sufficient experience (200 plate appearances or 200 batters faced at Double-A or higher) to forecast at least a cup of coffee in 2013. This group includes elite prospects such as the Cardinals' Oscar Taveras and the Pirates' Gerrit Cole.

We also identify each team's top rookie—right out of the Prospect Handbook—and the rookie with most potential for fantasy impact in 2013. Bear in mind that with few exceptions, such as Mike Trout and Bryce Harper last year, rookies are poor percentage plays in fantasy sports. That's why we recommend most rookies only in keeper or deep single-league formats.

ARIZONA DIAMONDBACKS

Rookies (4)
LHP Tyler Skaggs, SS Didi Gregorius, OF Adam Eaton, OF A.J. Pollock
No MLB Experience (8)
RHP Chase Anderson*, RHP Charles Brewer*, LHP Eury de la Rosa*, RHP Starling Peralta**, RHP Eric Smith*, RHP Zeke Spruill*, OF Keon Broxton*, OF Alfredo Marte*
On The Horizon
LHP David Holmberg, 3B Matt Davidson, SS Chris Owings

Top Rookie: Tyler Skaggs made three strong starts for Arizona before tiring in September and has a good chance to win a rotation job in spring training.

Fantasy Impact: A blend of speed and patience in the minors makes Adam Eaton a safe bet to accumulate runs and double-digit stolen bases for the Diamondbacks, and batting average risk is mitigated by a high contact rate. Just don't expect any contributions in home runs or RBIs. (Leagues: deep mixed) [...] Continue Reading »

Coming into the 2008 draft, Kyle Skipworth was considered to be one of the best high school catching prospects in years–a rare elite hitting prospect who could also do a solid job behind the plate.

Nearly five years later, the Marlins are still waiting for Skipworth to hit. But thanks to Jeff Mathis’ broken collarbone, it’s possible that Skipworth will begin the season in the big leagues, even though he struck out in nearly 35 percent of his at-bats last season and carries a career minor league batting line of .217/.285/.414.

In the Marlins’ case, Skipworth may be the best option on a team that really is without any legitimate options. Florida traded away catcher John Buck during the offseason and lost Brett Hayes on waivers. Rob Brantly, picked up in last summer's Anibal Sanchez trade, will be the starter, but until Mathis returns, the Marlins only other catcher on the 40-man roster is Skipworth. [...] Continue Reading »

John Lamb made his 2013 spring training debut on Sunday against the Rangers. It didn’t go particularly well, as Lamb gave up four hits and one run in one inning of work. A nicely timed double play and a well-placed curveball to strike out Yangervis Solarte with runners at first and third kept Lamb’s 2013 spring debut from being worse.

But for the Lamb, the bigger concern has to be his velocity on Sunday. The lefty sat in the mid-80s for most of his inning of work. He never touched 90 mph.

If Lamb's below-average velocity had first cropped up in this first spring outing, it could easily be written off as a pitcher rounding into form in spring training. But now 19 months since he had Tommy John surgery, Lamb has yet to regain the velocity that once made him the Royals’ best pitching prospect. [...] Continue Reading »