Three of the four guys getting regular playing time, CF/RF Cesar Puello (#6), RF Cory Vaughn (#32) and LF Travis Taijeron (#40) appeared on my pre-season Top 41 prospects list, while the most productive perhaps is CF/LF Alonzo Harris, who was unranked this year. Harris topped out on my list at #26 in 2010, but that was a postion ago, back when he was playing second base.
Coming into this year, I was highest on the youngest member of the outfield: the very strong Puello. He's responded with a lost year as a hammate bone fracture kept him off the field for much of the summer, and when he's played his strike zone control has deteriorated. His 2.4% walk rate just will not play regardless of how often he gets hit, as it reflects a more fundamental problem at the plate in identifying good pitches. Often hammate bone breaks result in power declines (or pauses in development), so it is hardly a surprise to see him hit relatively few homeruns. Still, he leads this list with a 9.6% extra-base hit rate. Puello was the FSL Mets' primary centerfielder in April and May when Darrell Ceciliani was out with his own hamstring problems. However, since his return to action on August 4th, he's played more rightfield (6 games) to center (3 games) out of deference to Alonzo Harris. I still like the tools, but the age clock is starting to tick a whole lot louder.
That subtle positional shift reflects how far Harris has come as a player this year on both sides of the ball. Harris has raked at a .319/.389/.469 rate with 23 walks and 25 strikeouts in 50 games in the second half. He's walking plenty, not striking out, hitting for a little pop and stealing bases. Oh, and he's playing centerfield. He was recruited as a Division I defensive back in football out of high school, so I think he has the speed and explosiveness for the postion. Harris' playing time went up when Ceciliani and Puello went down with injuries, and he's taken good advantage of the opportunity. It's hard to see an everyday player in a 23-year old in advanced-A, but his speed and defensive versatility (CF/LF/2B) could make him a fit on a big league bench.
Vaughn has cut his strikeouts down a little bit and shown the ability to hit the ball over the wall. Still, as a 23-year old corner guy, the .240 batting average indicates a serious problem making good consistent contact with a complicated swing. Vaughn has a persistent platoon split - .924 OPS vs. LHP in 139 AB this year and .747 in 281 AB vs. RHP. Scott Hairston has stuck around the big leagues because he crushes lefties and plays centerfield. Vaughn offers one of the two. For reference, Hairston blew through the hitters' paradise of Lancaster with a .405/.442/.797 mark in 18 games at age 22, and then hit .276/.345/.469 with 10 homers in his first crack at AA in 2003 as a 23-year old.
How does all of this affect prospect status? I'll still take the youth and massive shoulders of Puello among this group. However, Harris' very nice season at the plate, combined with the positional value in centerfield, should vault him over Vaughn.