Teenage Mutant Baseball Players

Bryce Harper has been a big mark on the baseball radar since 2009, when he graced the cover of Sports Illustrated. Later that year, Harper completed his GED a few weeks after his 17th birthday so that he could become eligible for professional baseball at a younger age than other American prospects. He enrolled at a junior college, where he broke the school's home run record and was named the conference player of the year. Harper was the 1st pick of the 2010 MLB Draft, taken by the Washington Nationals. He hit well in the Arizona Fall League that year, then did the same during the 2011 season, first in Class-A ball and then in AA. Many wanted him to start 2012 with the big league team, but not surprisingly he returned to the minors, this time to AAA. He hadn't hit much so far there this season, but today the Nationals announced Harper is being called up in time for tomorrow's game against the Dodgers, in Los Angeles.

Harper is only 19 years old, which will make him easily the youngest player in the Majors. In fact, the second youngest player, Toronto pitcher Drew Hutchison, is almost two full years older than Harper. Because Harper has been so hyped since before he was old enough to see R-rated movies without his mom, it might be expected that he's going to terrorize National League pitchers immediately and go on to an incredible career. I thought it would be interesting to look at other recent teenage call-ups, and see just what type of company Harper will be joining tomorrow night. In the last 25 years, there have been only fifteen other position players who made their Major League debut while still a teen. Some of them had only the proverbial cup of coffee in that first call up to the show, most played less than a quarter of that season. Harper has been called up far earlier in the season than most of those others, but of course it remains to be seen whether he stays up for the rest of the season, or is sent back down later on. Here are the fifteen others, in chronological order, with a look at how they performed in their call up season, and over the rest of their career (many of these players are active, those players' career number are through 4/26/2012):

Gary Sheffield - Brewers (SS)

1988: 24 G (games), 89 PA (plate appearances), .238/.295/.400, 4 HR, -0.2 rWAR 

Career: 2576 G, 10947 PA, .292/.393/.514, 509 HR, 63.3 rWAR, 9-time All-Star

Ken Griffey - Mariners (CF)

1989: 127 G, 506 PA, .264/.329/.420, 16 HR, 2.8 rWAR, 3rd in A.L. Rookie of Year voting

Career: 2671 G, 11304 PA, .284/.370/.538, 630 HR, 78.6 rWAR, 13-time All-Star

Juan Gonzalez - Rangers (CF/LF)

1989: 24 G, 68 PA, .150/.227/.250, 1 HR, -0.3 rWAR

Career: 1689 G, 7155 PA, .295/.343/.561, 434 HR, 33.5 rWAR, 3-time All-Star

Ivan Rodriguez - Rangers (C)

1991: 88 G, 288 PA, .264/.276/.354, 3 HR, 0.3 rWAR, 4th in A.L. Rookie of the Year voting

Career: 2543 G, 10270 PA, .296/.334/.464, 311 HR, 67.3 rWAR, 14-time All-Star

Alex Rodriguez - Mariners (SS)

1994: 17 G, 59 PA, .204/.241/.204, 0 HR, -0.4 rWAR

Career (active): 2420 G, 10713 PA, .301/.386/.566, 632 HR, 104.6 rWAR, 14-time All-Star

Karim Garcia - Dodgers (RF/LF)

1995: 13 G, 20 PA, .200/.200/.200, 0 HR, -0.4 rWAR

Career: 488 G, 1561 PA, .241/.279/.424, 66 HR, -3.5 rWAR

Edgar Renteria - Marlins (SS)

1996: 106 G, 471 PA, .309/.358/.399, 5 HR, 3.0 rWAR, 2nd in N.L. Rookie of the Year voting

Career: 2152 G, 9066 PA, .286/.343/.398, 140 HR, 31.7 rWAR, 5-time All-Star

Andruw Jones - Braves (CF)

1996: 31 G, 113 PA, .217/.265/.443, 5 HR, -0.1 rWAR

Career (active): 2110 G, 8425 PA, .256/.338/.488, 422 HR, 60.4 rWAR, 5-time All-Star

Aramis Ramirez - Pirates (3B)
1998: 72 G, 275 PA, .235/.296/.351, 6 HR, -1.6 rWAR
Career (active): 1701 G, 7033 PA, .283/.341/.498, 316 HR, 24.7 rWAR, 2-time All-Star

Adrian Beltre - Dodgers (3B/SS)

1998: 77 G, 214 PA, .215/.278/.369, 7 HR, 0.1 rWAR

Career (active): 1975 G, 8112 PA, .276/.329/.469, 313 HR, 47.6 rWAR, 2-time All-Star

Wilson Betemit - Braves (SS)

2001: 8 G, 5 PA, .000/.400/.000, 0 HR, 0.0 rWAR

Career (active): 709 G, 1994 PA, .268/.334/..448, 65 HR, 3.7 rWAR

Jose Reyes - Mets (SS)
2003: 69 G, 292 PA, .307/.334/.434, 5 HR, 1.8 rWAR, 8th in N.L. Rookie of the Year voting
Career (active): 1068 G, 4920 PA, .291/.340/.439, 81 HR, 29.3 rWAR, 4-time All-Star

B.J. Upton - Devil Rays (SS/3B/LF)

2004: 45 G, 117 PA, .258/.324/.409, 4 HR, 0.0 rWAR

Career (active): 826 G, 3452 PA, .257/.342/.416, 91 HR, 16.7 rWAR

Justin Upton - Diamondback (RF)

2007: 43 G, 152 PA, .221/.283/.364, 2 HR, -0.9 rWAR

Career (active): 597 G, 2462 PA, .276/.357/.484, 92 HR, 11.5 rWAR, 2-time All-Star

Mike Trout - Angels (CF/RF/LF)

2011: 40 G, 135 PA, .220/.281/.390, 5 HR, 0.9 rWAR

Career: Awaiting his own 2012 call up Called up only hours after Harper!

There are two points to take from looking at those fifteen players and their numbers:

1) Expectations for Harper in 2012 should be severely tempered. Griffey, Renteria, Reyes, and Trout were the only ones from that group that really contributed much value in their first season. Harper certainly has the potential to join them, but it's a lot more likely that he struggles against Major League pitching and possibly even goes back to the minors for a while. Nationals fans should not be concerned if that happens (and can enjoy Stephen Strasburg, their other phenom, in the meantime).

2) Expectations for Harper beyond 2012 can justifiably be sky high. Eleven of the fifteen others have played in multiple All-Star Games. Sheffield, Griffey, both Ivan and Alex Rodriguez, Jones, and Beltre all rank among the top fifty position players of the last twenty-five years. Griffey and Alex Rodriguez rank among the top ten of that time period. Players who get called up at such a young age tend to be incredibly talented, and there's a good chance that by 2017 Bryce Harper ranks very highly on a list of the best players in baseball.