To piggyback on Gordon Edes’ earlier post on the Arizona Fall League, which opens today, here is a breakdown of the prospects Boston is sending to the AFL to play for Scottsdale this fall:

• 3B Will Middlebrooks (23): Largely considered the top prospect in the organization at this point, Middlebrooks profiles as an above-average long-term regular at third base, with some All-Star potential. In 2011, the former fifth-round pick showcased a plus bat, plus power, decent speed, a plus arm and plus defense in Double-A Portland. However, he struggled after a late-season promotion to Triple-A Pawtucket, which was unsurprising given that he needs to continue to refine his approach against advanced pitching. He’ll get the opportunity to do just that in Arizona for the next six weeks. Look for Middlebrooks to start the 2012 season in Pawtucket, with a call-up to Boston in September, or possibly earlier if an injury situation arises.

• OF Alex Hassan (23): A local product from Milton (Mass.), Hassan has demonstrated phenomenal plate discipline at every level since the Red Sox drafted him in the 20th round in 2009. He makes above-average contact, but at this point projects to have below-average power for a corner outfielder unless he’s able to incorporate more lower body into his swing. A fringe-average fielder, Hassan has a strong enough arm for right field, but his lack of range may better suit him for left field. He’ll have to fight for playing time for Scottsdale this fall, given the presence of top prospects Bryce Harper, Mike Trout and Gary Brown on the Scorpions' roster. He’ll start the 2012 season in either Portland or Pawtucket, but where he breaks camp may be more of a result of an outfield logjam in Pawtucket rather than Hassan’s advancement.

• C Dan Butler (24): Butler went undrafted out of the University of Arizona in 2009, but impressed the Boston brass in a short stint in the Cape Cod League, prompting the club to sign him as an undrafted free agent. Butler proceeded to lead the Red Sox system in batting average in 2010 (min. 300 plate appearances), while demonstrating advanced defensive skills and an outstanding work ethic. He’s probably worked himself into becoming a candidate as an emergency major league backup option in 2012, depending on where Ryan Lavarnway is assigned to start the season and whether Luis Exposito can make it through the offseason without being waived to clear space on the 40-man roster. Over the long-term, Butler presently projects as a major league backup for a second division club.

• RHP Caleb Clay (23): A supplemental first-round pick in 2006, Clay has not lived up to expectations so far, suffering through a string of injuries in his five-year professional career. While he shows some promise as a reliever who induces a lot of ground balls with his sinking fastball, his performance has been subpar since returning from August 2007 Tommy John surgery. In 2011, he struggled with command, often leaving the ball up in the zone, and ultimately posted a 7.47 ERA with a 1.80 ERA and a 53/34 K/BB in 59 innings. If he can put up a good showing with Scottsdale this fall, he could be a candidate to either: (1) be a third chip in a major league trade; or (2) be selected in the Rule 5 Draft this December. If he’s back with the Sox in 2012, it will be for a return stint with Portland.

• SS Ryan Dent (22): Another former supplemental first-round pick that has failed to meet expectations, Dent has shown advanced defensive abilities at shortstop, but his bat has been below-average in nearly every respect. He has posted a career line of .221/.302/.342 with 21 home runs and 27 stolen bases in 361 minor league games over five seasons. Considering that he’s also able to play second base and center field adequately, he projects as a fringe utility player at this stage. Like Clay, he should also return for a second go-round with the Sea Dogs in 2012.

• RHP Brock Huntzinger (23): A third-round pick in 2007, Huntzinger went 5-11 with a 6.17 ERA for Portland this season. On the positive side, he posted one of the best strikeout-to-walk ratios in the organization in 2011, striking out 123 batters and walking just 41 in 124 innings. He mixes in a high-80s fastball, a tight low-80s slider, and an average high-70s changeup. He’ll need to work on improving his command and maintaining velocity if he wants to advance past Double-A. Huntzinger is probably a candidate for a move to the bullpen in 2012, likely back with Portland. If he’s able to work his velocity into the 92-93 mph range in short bursts and hone his slider, there’s some potential for the 23-year-old to become a back-end bullpen option at the major league level.

• LHP Will Latimer (25): As a 25-year-old who spent most of the 2011 season with High-A Salem, Latimer has not been on a major league track in the Red Sox system. His fastball sits around 88-90 mph with average movement and decent command, and he also mixes in an 82-84 mph slider. Latimer posted a 1.05 WHIP against left-handed batters in 2011, so there is an outside shot that he could develop into a left-handed specialist down the line.

• RHP Jeremy Kehrt (25): While Kehrt has far surpassed expectations for a 47th-round draft pick, posting adequate numbers between stops in Portland and Pawtucket in 2011, he does not presently project as a major leaguer. He simply doesn’t miss enough bats, while at the same time showing bouts of inconsistent control. He’s probably on the bubble for a roster spot with the PawSox in 2012, and could be on the outside of the bubble if Boston opts to bring in a slate of new major-league ready relievers to pitch for Pawtucket next season.