The Arizona Fall League provides an ideal forum for evaluating prospects. With players from all 30 organizations comprising six teams, the Fall League offers the unique opportunity to gauge young talent against competition that usually is superior to what they experienced during the Minor League season.
The preliminary rosters for this year's Fall League, released Wednesday, are loaded with future stars. The group features 11 players currently ranked on MLBPipeline.com's Top 100 Prospects list, including four in the Top 20, and there are many more who could contend for such a ranking next season with a strong showing in the desert.
But of all the talent selected to participate in this year's Fall League, these 10 prospects are the ones I most look forward to seeing.
The top-ranked prospect in this year's Fall League, Robles has seen his stock continue to soar in 2017 with his strong performance across two levels, including Double-A, where he's posted a .323/.396/.492 slash line and currently owns a 16-game hitting streak. The 20-year-old outfielder has begun to tap into his power this season en route to career highs in home runs (10) and doubles (35), and he continues to showcase one of the best combinations of tools in the Minors.
2017 Arizona Fall League rosters
Click on the AFL team name to see complete roster.
No prospect has made more noise this season than Acuna. The tooled-up, 19-year-old outfielder has flown through the Braves' system, hitting for average and power across three levels while also making an impact defensively and on the basepaths thanks to his well above-average wheels. Altogether, the teenage phenom produced a .322/.371/.521 slash line, with 20 home runs, 30 doubles and 42 steals.
Tucker will line up alongside Robles in Mesa's outfield, giving the Solar Sox a pair of must-watch power-speed prospects. The 20-year-old outfielder has posted 23 homers and 21 steals while posting a .269/.346/.518 slash line in 114 games this season, many of which he's spent in Double-A. As with Robles and Acuna, Tucker's time in the Fall League represents one of the final developmental hurdles ahead of his likely big league debut in 2018.
Mejia's designation as an infielder on Glendale's roster is no mistake. A catcher for all but two games in his career, the 21-year-old switch-hitter is expected spend the fall working at third base -- a position he played for the first time in a game on Wednesday. The Indians believe that increasing Mejia's defensive versatility will allow them to get his bat into the big league lineup sooner than later. He's certainly done his part this year in Double-A, posting a .297/.346/.490 slash line with a career-high 14 homers in 92 games.
The top-ranked AFL-bound hurler, Keller will use his time in the desert to make up for some of the time he lost earlier in the season due to a strained back. The 21-year-old righty proved too much for Florida State League hitters with his dynamic three-pitch mix, and he's been equally impressive with the move up to Double-A, posting a 3.19 ERA and a .205 batting average against with 105 strikeouts in 110 innings overall.
Urias has proved to be a special offensive player early in his career thanks his innate hitting ability and big league-caliber approach that belies his age. Those qualities have been on full display in his first Double-A campaign, with the 20-year-old middle infielder hitting .296 and reaching base at a .400 clip while accruing more walks than strikeouts for a fourth straight season.
After two fairly nondescript full-season campaigns, Chavis has put it all together this year to emerge as a premier power-hitting prospect. After totaling 25 home runs over his first 229 pro games, the 22-year-old third baseman has erupted to hit 30 home runs in 122 games in 2017, splitting the season between Double-A Portland and Class A Advanced Salem. More than just a slugger, Chavis also has made all-around offensive strides by posting a .289/.354/.570 slash line.
Acquired from the Dodgers last year in exchange for reliever Josh Fields, Alvarez, a 20-year-old Cuban, has put himself on the map this season by hitting a combined .312 with 12 homers and 69 RBIs between Class A Quad Cities and Class A Advanced Buies Creek. After seeing time both in the outfield and at first base during the regular season, Alvarez, a 6-foot-5 left-handed hitter, will receive the bulk of his reps at the latter position this fall.
Viewed as a projection pick who the Pirates made a first-rounder in 2014, Tucker has since tacked on quite a bit of muscle to his impressive frame without sacrificing any of his athleticism or speed. Those physical gains have translated to a breakout season for the 21-year-old shortstop, as he's produced a .271/.349/.400 slash line with 34 extra-base hits and 44 steals while reaching Double-A.
Zeuch, Toronto's first-round Draft pick in 2016, is headed to the Fall League to make up innings after spending roughly two months of his first full season on the shelf with back issues. The 6-foot-7 right-hander has impressed when healthy, however, showing an advanced four-pitch mix and extreme ground-ball tendencies that have netted him more than three times as many groundouts than air outs in the Florida State League.
Mike Rosenbaum is a reporter for MLB.com. Follow him on Twitter at @GoldenSombrero. This story was not subject to the approval of Major League Baseball or its clubs.