There are various reasons prospects are assigned to the Arizona Fall League.
Many of the AFL players are returning from injury and need additional at-bats or innings on the mound to continue their development. Some prospects are close to being ready to contribute at the Major League level. For those players, the league helps to refine their skills against quality competition.
Hak-Ju Lee, 22, is a left-handed-hitting shortstop prospect of the Tampa Bay Rays. His assignment to the AFL may have been responding to both of those factors.
The Arizona Fall League is where I recently saw Lee play a number of games.
Lee injured his oblique late in the 2012 season at Double-A Montgomery of the Southern League. Playing in the AFL offered him additional at-bats and an opportunity to catch up against high quality pitching.
Many scouts and talent evaluators have viewed Lee as the shortstop of the future for Tampa Bay. MLB.com ranks Lee as the No. 3 prospect in the Rays' system, which is not particularly deep in middle infielders.
Because of the Rays' lack of infield depth, Lee's presence in Arizona may have originally been intended to prepare him for a promotion to the Major League club at some point in the 2013 season.
However, that scenario most likely changed with the arrival of shortstop Yunel Escobar via trade from the Miami Marlins. It appears Escobar will be the Rays' starting shortstop.
Not known to rush its prospects, Escobar's presence may provide Tampa Bay the opportunity to allow Lee to gain additional time to develop.
Lee is a native of Jeonju, South Korea. He signed a professional contract with the Chicago Cubs in 2008. Tommy John surgery delayed his debut until the '09 season.
Lee is a lanky 6-foot-2, 170 pounds with rather long legs and a wiry lower body. He has solid upper body strength.
Lee got off to a good professional beginning, hitting .330 with two home runs and 33 RBIs for Class A Boise in 2009. He stole 25 bases that first season, getting caught eight times. He showed he could make good contact, striking out only 50 times in 304 plate appearances.
In January 2011, the Cubs traded Lee to Tampa Bay along with pitcher Chris Archer, catcher Robinson Chirinos, outfielder Sam Fuld and outfielder Brandon Guyer for right-handed starter Matt Garza, outfielder Fernando Perez and pitcher Zachary Rosscup.
The Rays assigned Lee to Class A Charlotte to begin the 2011 season. He responded by hitting .318 and stealing 28 bases in 454 plate appearances.
His performance earned Lee an in-season promotion to Double-A Montgomery, where he scuffled a bit. He had 114 plate appearances in Montgomery, but he hit only .190.
This past season, Lee returned to Montgomery, where he hit .261 with 10 triples and 68 runs scored in 534 plate appearances. Lee stole 37 bases and was caught stealing nine times.
Lee is a line-drive hitter with not much home run power. Although I see projectable offensive skill, Lee struggled at the plate in the AFL. He finished the AFL season hitting only .247. He stole three bases and was caught stealing five times. He struck out 21 times and walked 11 times.
Using a fairly level stroke, Lee has the ability to take pitches to any part of the field. In many at-bats I observed, he seemed to thrive on high fastballs and other pitches up in the zone.
Looking at his fall statistics, it would be easy to conclude Lee is strictly a singles hitter. Of his 20 hits in 81 at-bats, 19 were singles and one was a triple.
Lee certainly has the speed to take extra bases. If he can add a dimension of power to his game, his offensive value will increase. It will require him to seek pitches he can drive and avoiding trying to do more than his capabilities allow.
Overall, I believe he does have the ability to hit those high pitches to both the right-field and left-field gaps. It just didn't materialize this past fall. Based upon his swing mechanics, physical build and plate coverage, I see projectable gap power.
That said, his current line-drive hitting approach and swing mechanics may yield a better batting average than if he tried to become more of a power hitter. Keeping the ball on the ground and using his speed may ultimately be his best approach.
Lee doesn't always get a good read of the pitcher or the best jump when trying to steal second. That, too, should improve.
While I think Lee may eventually become an average Major League hitter, it is his defense and speed that project to be his best tools.
Lee has outstanding first-step quickness at shortstop. His range is good to all directions. He gets to many balls that could easily become base hits. His transfer and release from glove to hand adds to his very fluid approach.
If I saw any flaw in Lee's defensive play, it was his occasional careless throws to first base. His arm is strong. If anything, I believe his footwork prior to his throws may be a culprit that could cause some throwing errors. He could have benefited from taking more time to plant his feet and then release the ball. He made five errors in 72 chances this past fall, a bit too many for a player with his skill.
Although I think Lee will be able to hit quality pitching, I believe he projects as a solid, defense-first Major League shortstop. His speed and quickness add important dimensions to his value.
Bernie Pleskoff has served as a professional scout for the Houston Astros and Seattle Mariners. Follow @BerniePleskoff on Twitter.