Major League Preview

2012 Preseason Top 20 Rookies

Here are our picks for the 20 rookies most likely to stand out in 2012.
1. Matt Moore, lhp, Rays
Age: 22.

Best Case Scenario: Moore slides into the middle of the Rays' rotation and gives them another dominant arm as they not only return to the playoffs but also have the firepower to get back to the World Series.

Worst Case Scenario: Moore goes through the more normal rookie growing pains and occupies more of a back-of-the-rotation role, getting shut down at the end of the year to control his workload.

Competition: Wade Davis, Jeff Niemann.
2. Yu Darvish, rhp, Rangers
Age: 26.

Best Case Scenario: A 21st century version of Nomomania, Darvish shows the same dominant stuff in the United States that he did in Japan and provides the Rangers the missing ingredient they need to win the World Series.

Worst Case Scenario: Darvish pitches more like Daisuke Matsusaka and struggles with the increased demands of pitching every five days for six or seven months.

Competition: None
3. Jesus Montero, c/dh, Mariners
Age: 22.

Best Case Scenario: Montero hits like he did in his New York cameo late last season and provides the power bat the Mariners lineup desperately needs, not to mention showing better skills than expected behind the plate.

Worst Case Scenario: Montero's work behind the plate is bad enough that he plays only at DH, and he gets dragged down by the Mariners' anemic lineup.

Competition: Miguel Olivo, Carlos Peguero
4. Mike Trout, of, Angels
Age: 20.

Best Case Scenario: Trout impresses in spring training enough to earn a spot in the Opening Day lineup, and he showcases the same skills in the majors that he has in the minors, propelling the Angels past the Rangers.

Worst Case Scenario: Vernon Wells bounces back and other Angels veterans perform, leaving nowhere for Trout to play. He puts up big numbers in Triple-A and repeats as the BA Minor League Player of the Year.

Competition: Vernon Wells, Peter Bourjos, Torii Hunter
5. Yoenis Cespedes, of, Athletics
Age: 26.

Best Case Scenario: Cespedes shows no rust from the layoff since his defection from Cuba and gives the Athletics the cornerstone bat they've been trying to find for years.

Worst Case Scenario: The layoff and adjustment to U.S. pitching prove too much for Cespedes to overcome, and he has to spend time in the minors to get his swing ironed out, raising fears that he'll be another overhyped Cuban defector.

Competition: Seth Smith, Coco Crisp, Josh Reddick, Collin Cowgill
6. Julio Teheran, rhp, Braves
Age: 21.

Best Case Scenario: Teheran becomes the next great Braves pitcher, winning a spot in the Opening Day rotation and helping the team erase the memory of last year's collapse.

Worst Case Scenario: Unable to find a spot in a crowded rotation out of spring training, Teheran proves once again that he can dominate Triple-A hitters while waiting for the inevitable injury in Atlanta.

Competition: Mike Minor, Randall Delgado
7. Zack Cozart, ss, Reds
Age: 26.

Best Case Scenario: Cozart is the rare rookie who earns Dusty Baker's full trust, playing every day at shortstop and putting up good numbers in a strong lineup and favorable hitter's park.

Worst Case Scenario: Baker goes with a more proven commodity, sending Cozart back to Triple-A for a third straight year.

Competition: Paul Janish, Wilson Valdez
8. Devin Mesoraco, c, Reds
Age: 23.

Best Case Scenario: Provides above-average offensive production for a catcher combined with adequate defense as a rookie on an NL Central contender.

Worst Case Scenario: Mesoraco's injury issues of the past crop back up, cutting into his production and playing time.

Competition: Ryan Hanigan
9. Jarrod Parker, rhp, Athletics
Age: 23.

Best Case Scenario: Parker's improved mechanics and developing changeup allow his plus stuff to make an instant impact in an A's rotation that needs the help.

Worst Case Scenario: Parker has the growing pains that many rookie starters endure, even the ones with plus stuff. With the A's rebuilding effort, he'd still likely receive 20 starts.

Competition: Tom Milone, Sonny Gray, Brad Peacock.
10. Bryce Harper, of, Nationals
Age: 19.

Best Case Scenario: Harper's power potential makes him the toast of D.C. as he threatens Tony Conigliaro's single-season record for home runs as a teenager (24).

Worst Case Scenario: Harper shows flashes of his prodigious talent, but like Alex Rodriguez and other prodigies before him, he struggles in his initial look at big league pitching.

Competition: Mark DeRosa, Roger Bernadina, Rick Ankiel.
11. Yonder Alonso, 1b, Padres
Age: 24.

Best Case Scenario: Finally given a chance to play every day at this natural position, Alonso provides solid average, on-base percentage and power.

Worst Case Scenario: Pitcher-friendly Petco Park saps his numbers, although considering his competition, Alonso is still likely to pile up plenty of plate appearances.

Competition: Jesus Guzman, Kyle Blanks.
12. Brad Peacock, rhp, Athletics
Age: 23.

Best Case Scenario: Peacock's meteoric rise to top prospect continues with a solid season as a middle-of-the-rotation starter for a young A's staff.

Worst Case Scenario: After his sensational 2011 minor league season, Peacock gives back a little of the command and velocity gains he saw last year and finds he still needs to refine his secondary stuff.

Competition: Jarrod Parker, Tom Milone, Sonny Gray.
13. Drew Pomeranz, lhp, Rockies
Age: 23.

Best Case Scenario: After an appendectomy and a long season saw his usually plus fastball dip to pedestrian levels late in 2011, Pomeranz re-establishes himself as a power pitcher while locking down the Rockies' No. 3 starter job.

Worst Case Scenario: Pomeranz's command, never a strong suit at Ole Miss, continues to be a problem and he finds pitching at Coors Field can be unforgiving.

Competition: Alex White, Guillermo Moscoso, Tyler Chatwood, Josh Outman, Esmil Rogers, Jamie Moyer.
14. Addison Reed, rhp, White Sox
Age: 23.

Best Case Scenario: Much like Sergio Santos last year, the White Sox's unsettled bullpen gives Reed's talent a chance to shine as he earns the closer job by May.

Worst Case Scenario: Matt Thornton takes charge of the closer's job this year after failing to do so in 2011, which leaves Reed working as a hard-throwing set-up man all year.

Competition: Matt Thornton, Jesse Crain, Jhan Marinez.
15. Brett Jackson, of, Cubs
Age: 23.

Best Case Scenario: Jackson's solid-to-plus tools across the board earn him the starting center field job, and he gives Cubs' fans a young star to get excited about.

Worst Case Scenario: Alfonso Soriano and Marlon Byrd's combined $24.5 million salary keeps Jackson waiting a while longer to get a chance to roam among the ivy in Wrigley.

Competition: Marlon Byrd, Tony Campana, Dave Sappelt.
16. Shelby Miller, rhp, Cardinals
Age: 21.

Best Case Scenario: Injuries and ineffectiveness for Kyle Lohse and Jake Westbrook force the Cardinals to speed up Miller's timetable. Once he arrives in St. Louis, his plus-plus stuff handles the rest.

Worst Case Scenario: Miller finds his first taste of Triple-A tougher than he expected, pushing his timetable back to 2013.

Competition: Kyle Lohse, Jake Westbrook.
17. Leonys Martin, of, Rangers
Age: 23.

Best Case Scenario: Martin wins the center field job in spring training and proves to be the leadoff hitter the Rangers are expecting he can be while providing quality defense in center field.

Worst Case Scenario: Martin's inability to turn raw power into game situations continues, allowing pitchers to overpower him. That eventually forces Texas to move Josh Hamilton back to center field for the playoff run.

Competition: Julio Borbon, Craig Gentry.
18. Trevor Bauer, rhp, Diamondbacks
Age: 21.

Best Case Scenario: The most big league ready pitcher in last year's draft brings his varied arsenal to the big leagues, inspiring young pitchers around the country to educate themselves about pitching mechanics and training.

Worst Case Scenario: The Diamondbacks' crowded rotation means Bauer spends a full season in the minors waiting for the opportunity to come up.

Competition: Josh Collementer, Barry Enright, Wade Miley, Tyler Skaggs.
19. Jacob Turner, rhp, Tigers
Age: 20.

Best Case Scenario: The big league struggles of 2011 prove a useful teaching moment for Turner, who puts up numbers similar to what Rick Porcello provided as a 20-year-old in 2009 (14-9, 3.96 in 31 starts).

Worst Case Scenario: Turner continues to pound the zone, but his lack of strikeouts leads to a season that looks more like 2010-11 Porcello.

Competition: Adam Wilk, Casey Crosby, Andy Oliver.
20. Arodys Vizcaino, rhp, Braves
Age: 21.

Best Case Scenario: Manager Fredi Gonzalez leans less on the Johnny Venters/Craig Kimbrel/Eric O'Flaherty terrific trio, providing a chance for Vizcaino to provide quality innings and blistering stuff in the Braves' bullpen.

Worst Case Scenario: A veteran of back and elbow injuries, Vizcaino breaks down under the weight of Gonzalez's bullpen usage and his first full season in the role.

Competition: Jairo Ascenio, Kris Medlen, Cristhian Martinez.