Francellis Montas, RHP, White Sox (Glendale Desert Dogs)

Montas dealt with a knee injury that limited him to only 81 innings during the season, so his assignment in the Arizona Fall League is mostly about getting him some more work to finish out the year. The big right-hander’s main draw is a monster fastball that works 96-99 mph, with the ability to touch triple digits, and an 88-90 mph slider that has consistently been tightening over the last couple of seasons. While Montas has been working as a starter for the White Sox, I see the overall package playing out of the bullpen over the long-haul due to a max effort delivery and an arsenal that points more towards two viable pitches. His changeup does lag considerably behind the other two offerings. This is an arm that, if everything breaks right, can line up as a closer at the highest level. I’m intrigued to see Montas square off against the high caliber competition of this type of setting. The fastball and slider are likely to draw some rave reviews from evaluators in attendance, with the overall buzz on the arm having a good chance to swell heading into the offseason. –Chris Mellen

Daniel Robertson, SS, Athletics

The departure of Addison Russell this summer, and the likely departure of Jed Lowrie this off-season, could leave the Athletics with a hole at the six-spot, both in the short and long term. While evaluators have generally viewed Robertson as a candidate to shift off of short, and sooner rather than later, the 2012 first rounder completed another full season at the premiere defensive spot on the dirt. Further, he appears to be slowly winning over hearts and minds, with a growing narrative giving him a shot to at least start off his major league career at shortstop. The bat continues to impress, with Robertson leading the California League in hits in 2014, and the transition from the hitter-friendly Cal League to the hitter-friendly Arizona Fall League should help Robertson continue to put forth solid production, even with a step up in competition. But evaluators, and the Athletics in particular, will be sitting on the glove, the footwork, and the arm over the next six weeks. If Robertson can continue to hold his own at short he could simplify things for the front office as they look ahead to 2015 and beyond. –Nick J. Faleris

Tyler Glasnow, RHP, Pirates (Scottsdale Scorpions)

Glasnow mowed down Florida State League hitters this season, fanning 157 batters in 124 innings while sporting a shiny 1.74 ERA in 23 games started. While the numbers are certainly impressive, reports on the 21-year-old’s stuff have been downright intoxicating. His heater sits 94-97 and will touch triple digits on occasion and is made even more untouchable due to the massive plane and extension he achieves in his delivery. Reports on the curveball have improved over the season, giving the righty the chance to have an elite offering in the fastball and another swing-and-miss pitch with the hammer. The changeup and the overall command profile are both still in development, but the necessary components are there for each to become adequate at the highest level. The total package is that of a frontline starter given the necessary developmental strides, but the excitement regarding the AFL is based solely on his capability to shove it in the three-to-four-inning stints that are typically associated with starting pitchers in the AFL. Given the electricity of his arsenal, Glasnow certainly has the ability to wow evaluators when he ramps it up in shorter bursts. –Ethan Purser

Justin O'Conner, C, Rays (Peoria Javelinas)

Drafted out of a small Indiana high school in the first round of 2010, O'Conner has stopped at every level in the Rays system. After relatively disappointing statistical outputs in his first few professional campaigns, O'Conner started to break out in 2014; posting a .278/.316/.466 line between High-A and AA and mashing 49 extra base hits. The prep product has always been viewed as a long-term project. Coming out, scouts were intrigued by the package of plus raw power, athleticism, and a cannon of an arm. This year, the tools have started to actualize into usable baseball skills. The catcher is gifted with an elite arm, causing evaluators to turn their stopwatches toward each other and smirk. Often he posts times in the low-to-mid 1.7s, and has been clocked as low as 1.68 this season. It's nice to have an absolute hose for an arm and quick release, but O'Conner also sports plus defensive potential and excels as a blocker.

The defensive chops have always been apparent, but the catcher has started to open up eyes with his offensive potential. O'Conner has taken a big step forward in the batter’s box, adjusting to off-speed pitches and refining his overall approach. What looked to be a defense-first backup catcher or weak side of a platoon as recently as last offseason, may now offer the promise of an everyday backstop. His plus raw power is starting to turn up in games, and if the hit tool manifests to fringy, the game power could be solid average.

It will be interesting to see if O'Conner can keep up his more refined approach in the AFL against more advanced pitching. If so, he's in the mix toward the back end of the BP top 101, making it entirely possible that we look back at 2014 as his coming out party. –Jordan Gorosh

Tyrone Taylor, OF, Brewers (Glendale Desert Dogs)

Pure athleticism can be one of the most fascinating aspects of a prospects' game to watch on the field. However, many highly athletic prospects often fail to develop their raw tools into baseball skills. Players such as Michael Taylor and Billy Hamilton are still molding their game, but are generally the exceptions to the rule. This baseball development often takes years to click, and one of my main interests in the AFL is to see how far along this path Tyrone Taylor has journeyed. The defense and speed are his carrying tools, both registering as plus or higher. The main concern has always been at the plate, and whether he can consistently string together good at-bats. He has slumbering raw tools, with good pop that derives from plus bat speed. The AFL will be a great test for the athletic Taylor, and it will begin to shed some light on just how much further he really needs before the tools begin to develop into applicable skills on the diamond. His progression as a hitter will be important and the deciding factor on whether he is a solid role 4 outfielder or an impact player in center field. –Tucker Blair

Domingo Leyba, 2B, Tigers (Glendale Desert Dogs)

The Tigers are notoriously aggressive in promoting prospects through their minor league system, and that trend continues with extremely pushy move that sends 19-year-old second baseman Domingo Leyba to the Arizona Fall League. Leyba is a quality talent with an uncanny knack for getting the bat to the ball. He maintains a tremendous belief in his natural ability, and that belief comes with a swagger on the field that may allow him to succeed in the limited opportunities he is likely to receive this fall. Leyba is presently a pretty one dimensional player with few skills outside of his ability to make consistent contact. Still underdeveloped physically, Leyba is a small kid with limited strength and he is only a solid runner. He does well defensively at second base, but the game still moves quickly for him at times. For a player that is still clearly in the early stages of his developmental path, Leyba makes you pay attention to him on the field, and finding success in the AFL – even if in a limited, taxi squad type role – would allow the Tigers to get aggressive with his assignment in 2014, possibly pushing him to High-A before mid-season. Either way, 19-year-olds with limited stateside experience are always intriguing in environments like the AFL, and Leyba’s precocious bat-to-ball ability will make him someone worth following over the next few weeks. –Mark Anderson

Raul Mondesi, SS, Royals (Peoria Javelinas)

In life, I hate being wrong. But as an evaluator, I want to be wrong when I find myself much lower on a top prospect than other scouts. Such is my predicament with Royals shortstop prospect Raul Mondesi and why I need a better look at him this fall.

I've seen him only briefly in person, so I haven't developed a firm stance on the son of the former Dodgers outfielder of the same name, but what I've seen are the tools that evaluators salivate about in a package unprepared to use them. The speed is undeniably evident, as are the actions in the field, which will make for a major league caliber shortstop once he repeats them more consistently.

But at the plate, his tools – which include plus bat speed, average raw power, and the aforementioned speed – are dulled by an incredibly unrefined reproach that results in an impressive collection of poor contact. He has been young for every level in which he's participated, in the same way that that kid who went to college at 13-years-old was young for his grade, and the AFL will be no different. In fact, it will be his biggest test yet. I believe Mondesi has the tools to be a good hitter, but I need to see a better approach to make it happen. I don't expect to see major steps taken in the desert in his toughest test to date, but perhaps the influence of much older hitters will point him in the right direction. Regardless, it's an opportunity to see him again and see if those tools show any signs of translating into offensive production. –Jeff Moore

Tayron Guerrero, RHP, Padres (Surprise Saguaros)

I’m not one to make appointments to go see relief prospects. They don’t do much for me and the burnout rate is crazy high for two-pitch pitchers who work out of the bullpen. I’m a reasonable man, however, and I do make exceptions when the prospect dictates it. Generally they’re for former position players turned pitchers and for guys who throw in the upper 90s with a secondary offering that has wipeout potential. Tayron Guerrero falls in the latter group as he has a fastball that flirts with 100 and a slider with good tilt and break that operates in the low 90s. Guerrero is a tall, lanky guy, listed at 6-foot-7 and 200 lbs. The long levers and quick arm action combined with serious downward plane and a 96-plus-mph fastball is an enticing package, and it’s one that I’m eager to see against advanced hitters in the AFL. Guerrero hasn’t faced this level of competition on a consistent basis yet. He has yet to escape High-A ball and 2014 represented the first time in his career that the results started matching the stuff. Guerrero is a reliever, sure, but he’s an exciting one with real closer type stuff. –Mauricio Rubio

Michael De Leon, SS, Rangers (Surprise Saguaros)

Armed with a competent glove, a quality arm, and a bat that he’s growing into, De Leon could be yet another one of the Rangers’ up-the-middle finds, and the organization’s confidence in De Leon’s makeup and ability is evident from his extremely aggressive assignments. In May, I saw De Leon demonstrate a mature approach in the field, handling difficult balls hit his way with ease, but his three at-bats had all the awkwardness of a 17-year-old against Double-A pitching. His solitary hit was a bloop double on the line, and only a burst of secondary speed from the youngster kept it from becoming an out at second. During batting practice, De Leon showed a contact-minded swing that was better from the right side but also an inability to get around on any pitch consistently — something that will hopefully be rectified as his body matures. His numbers in Hickory (.244/.302/.295, 40 strikeouts, and 28 walks in 85 games) show that his raw ability to initiate contact is advanced beyond his age, despite some issues with the swing. –Kate Morrison

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There are a lot of interesting prospects going. It must've been hard to pick out just those eight.
Can't wait. I am heading out to AZ today and will be there for most of the league. I hope to see some of you guys out there.
We will have a group at the fields at the end of the month. I will be down in Florida, but you'll definitely have some BP Prospect Team members to chat up!
Great! I'll be on the lookout for the team!
I'm looking forward to seeing how Roman Quinn looks. He had a pretty nasty injury to start the year but, from what I understand, looked good once he came back. Plus, he's finally been moved off SS and is now in CF where he probably belongs.

For Houston fans, all eyes will be on Mark Appel and Vince Valasquez. Appel needs to pitch well, and be ready to start the season in AAA with a late season trip to Houston. Valasquez will have a chance to accomplish the same thing. Given this year's draft debacle, Luhnow needs these two guys to front the rotation in 2016 and this fall should give us a chance to evaluate where these guys are in the process.
Is it unusual for a guy like Glasnow to be in the AFL? I feel like it's rare to see a top pitching prospect out there especially coming off a 124 inning season.
And another one in Zimmer will be there.

I definitely think you see more hitting prospects than pitching ones.