Bryce Harper vs. Will Middlebrooks: Which Stud Prospect Will Have Bigger 2012?

Over the last week-and-a-half, prospects Bryce Harper and Will Middlebrooks—as well as Mike Trout—have commanded the praise of fans throughout baseball. Both players have excelled in the wake of an injury to a teammate, with Harper getting the call and carrying the Nationals following Ryan Zimmerman’s trip to the disabled list, and Middlebrooks providing similar production in place of an ailing Kevin Youkilis.

Having started all nine games since his promotion, Harper enters Wednesday’s game batting .300/.405/500 with six doubles, three RBI and five walks in 37 plate appearances. 

Not to be outdone, Middlebrooks has posted a .409/.435/1.000 slash line with four doubles, three homes runs and nine RBI in 23 plate appearances.

But which player will have a better rookie season? Here is what both prospects' current 2012 ZIPS projections look like, according to FanGraphs.com:

Harper: .244/.327/.413, 453 PA, 27 2B, 12 HR, 48 RBI, 103 K, 48 BB, 18 SB, 2.2 fWAR

Middlebrooks: .259/.294/.450, 449 PA, 28 2B, 17 HR, 53 RBI, 118 K, 20 BB, 2.2 fWAR

Obviously, such a small sample size can be very misleading. For example, in Middlebrooks' minor league career, the third baseman has fanned between 23 percent and 33 percent of the time in every season.  Since arriving in the major leagues, he’s currently fanning 21.7 percent of the time.

Now, almost never does a prospect’s plate discipline suddenly improve upon reaching the Show; the quality of off-speed pitches and a pitcher’s ability to locate them always plagues young hitters at some point in a given season. And considering both Middlebrooks’s approach and lengthy, lofty swing, I see him being more vulnerable at the dish than Harper as the season progresses.

I’m not saying that Harper won’t accumulate his fair share of strikeouts and scuffle over the course of a season, but his strikeout rate has been steadily improving since entering the minors in 2010 and he's shown an advanced plate discipline since arriving in Washington.

While each player’s legitimate power to all fields will make their strikeout totals tolerable, such an attribute is still a product of plate discipline. 

Therefore, Harper’s knack for consistent contact (as a result of superior plate discipline) should give him a greater chance to be more successful than Middlebrooks this season. While both players have the potential for Rookie of the Year-caliber production in their respective leagues—especially considering that they are both making an impact in early May—Harper appears more likely to continue his current offensive production.

What do the Prospect Pipeline readers think? Feel free to share your thoughts in the comments section below.