The Rockies system isn't overly deep. However, it is headlined by a couple of prospects that are unanimously considered top 100 prospects by industry experts. Also, most of the prospects featured here will be making an impact in the majors in short order.
Top 5 fantasy prospects
1- Nolan Arenado, 3B
Arenado made enough strides in the field to silence many of his defensive critics. His bat, though, is what makes him one of the best third base prospects in baseball. He already showed a penchant for making contact, but took that skill to new heights in 2011 striking out in fewer than 10 percent of his plate appearances. He began tapping into his home run potential hitting 20 bombs in 517 at-bats in High-A. He followed up a sterling season in High-A by scorching the ball in the Arizona Fall League (AFL) to the tune of a .388/.423/.636 line. As the small gap in batting average and on-base percentage indicates, he didn't walk a lot (6.2 percent walk rate), but that shouldn't be too concerning since his 8.1 percent walk rate in High-A was fine.
He impressed the Rockies front office in 2011 enough that the team has stated he'll have a chance to win the starting third base gig in the spring. While that sounds great, I'm not buying it. He hasn't taken so much as one at-bat in Double-A, and the leap from High-A to the majors is huge. While I'm not buying into the thought of him starting at third base for the Rockies on Opening Day, I am buying into him hitting his way to the show during the summer. His friendly home confines should help him hit more than 20 home runs yearly with a high average. That's golden from the hot corner.
2- Drew Pomeranz, SP
The Rockies sent Ubaldo Jimenez to the Indians for a large package at the trade deadline in 2011. The premier piece n the package was Pomeranz. He is a big southpaw with plus velocity on his fastball, 90-95 mph, and a knee buckling curveball. His third offering is a below average change-up that he'll continue to need to work on. His two pitch mix was good enough to dominate hitters and sport a 1.78 ERA in 101 innings at Hi-A and Double-A combined. He struck out better than a batter per inning (10.6 K/9), and demonstrated passable control (3.39 BB/9). Pomeranz was able to get more ground outs than fly out in High-A, but hitters took to the air against him in Double-A. If he hopes to avoid some of the pitfalls of pitching at Coors Field, he'll need to get back to inducing ground outs. In four starts with the Rockies, he had a 47.4 percent groundball rate, so it's promising he'll be able to limit long ball damage. Pomeranz will have a chance to open the year in the Rockies rotation.
3- Chad Bettis, SP
Drafted out of Texas Tech in 2010 as a swingman (part time starter, part time closer), the Rockies decided to give him a shot to start games. They have been rewarded for that decision. Bettis dominated in Short-Season ball, and Low-A after signing. He didn't slow down much playing in High-A in 2011. He features a hard sinking 93-95 mph fastball that can touch a few ticks higher, and a nasty swing-and-miss slider. His other secondary offerings, a change-up and curveball, are currently below average. If either of the softer offerings develops to even average, he could be a fantasy asset as a starter. If neither does, his fastball/slider combo gives him the power offerings to succeed as a closer. He'll open the year in Double-A.
4- Wilin Rosario, C
Rosario stayed healthy returning from surgery to repair a torn ACL in 2010. He got back to hitting for power, but still is dogged by an awful walk rate. He'd be best served learning to take a few more walks, but at worst, should provide power to fantasy owners if he isn't completely undone by his approach. He's the favorite to serve as Ramon Hernandez's backup this year.
5- Tim Wheeler, OF
Wheeler hit a ton of bombs in Double-A this past year, 33 to be exact. He also stole 20 bases. That's the good. The bad is that he strikes out a ton, struggles with lefties, was partly aided by a home ballpark that enhanced home run production by 11 percent according to Jeff Sackman's and Dan Szymborski's minor league ballpark factors found at Baseball Think Factory, and is a woefully inefficient base stealer. The power and speed combination keeps could make him a fantasy contributor with regular playing time, but don't be fooled by the glowing raw stats.
Bonus- Trevor Story, SS/3B
Story was a supplemental first round draft pick of the Rockies in 2011. He may have enough defensive skills to stick at shortstop, and will be developed there for now, but will likely eventually shift to third base so that he can play next to Troy Tulowitzki. He signed quickly enough to play in 47 games at the Rookie League level, and he should open in Low-A. He should hit 15-20 home runs, and add as many stolen bases. His ability to hit for a decent batting average will be contingent on him cutting down on his strikeout rate a bit.
Top 5 in 2012
1- Drew Pomeranz, SP
Pomeranz will have a chance to open with the Rockies. He'll likely have his share of struggles like most young pitchers, but his strikeout potential is great enough to give him a shot to be a fantasy option in deep mixed leagues and NL-only formats.
2- Nolan Arenado, 3B
His best days will come after this year. That said, if he's able to hit his way to the majors by the early-to-mid summer, he could provide value as a spot play at third base or corner infield in large mixed leagues or NL-only formats.
3- Wilin Rosario, C
The bar is set very low in two catcher leagues, and Rosario has power. You do the math.
4- Charlie Blackmon, OF
Blackmon will open the year as the fourth outfielder for the Rockies. He could see more playing time than your average fourth outfielder with one of the team's starting outfield spots being filled by Swiss army knife Michael Cuddyer. Blackmon already has seen time in the majors, receiving 103 plate appearances for the Rockies in 2011. He makes enough contact to suggest he'll hit .275 or better, and he has enough power and speed to be a modest contributor in home runs and steals as well.
5- Tim Wheeler, OF
Wheeler will be in Triple-A to start 2012, but will need a rash of injuries at the big league level to receive regular playing time. That's possible, though, and there weren't many other high minors options to round out this list.