Many Arizona Fall League participants see Major League Baseball action the following season. Fantasy baseball players must identify noteworthy AFL prospects. Which can help their fantasy baseball teams? Rising MLB youngsters often make fantasy baseball noise.

Catchers

Tony Sanchez, Pittsburgh Pirates

In June, a fastball to the jaw ended Sanchez's regular season. As observers pointed out, the devastating injury doesn't seem to have fazed him in the box. The Bucs' top pick of 2009 hit four homers in 68 AFL at-bats but posted a poor average. He has a quality approach, although he may never be more than an above-average hitter. Excellent defensive skills make him a future staple, but don't look for him until 2012.

• The Cincinnati Reds' Devin Mesoraco, 22, has problems with gear strapped on, but he had an eye-opening performance at the plate this year. He wasn't very selective (one walk, 15 K's) in the AFL, and he struggled after a fast jump to Triple-A ball. Still, Mesoraco packs some serious punch and could debut next year.
• The Washington Nationals moved Bryce Harper to the outfield for many reasons. Perhaps Derek Norris' patience and promising power aren't bad consolation prizes, although there's still uncertainty about his defense.

Corner infielders

Brandon Belt, San Francisco Giants

Hype has a name ... and is exciting

Prospect hounds marvel at the success Belt has experienced since the Giants overhauled his swing last year. He has excellent gap power that, with some more meat, projects to become consistent ding dong clout. Some call him the best first base prospect behind the Kansas City Royals' Eric Hosmer. Brian Sabean has already hinted that Belt could be a factor in 2011. What happens with Aubrey Huff and in left field will influence that. Belt is a buy.

Zack Cox, St. Louis Cardinals

The Cards' 2010 first-rounder (25th overall) was considered one of the best college hitters in the draft. He's also on enough of a fast track that St. Louis is considering trading David Freese. Evaluators, in limited looks, questioned his offensive and defensive ability, but, to be fair, Cox hadn't played much since college ball. He picked it up in his final 10 AFL games (.324-2-10). It's worth monitoring how St. Louis plays this in late spring.

• The Los Angeles Dodgers' Jerry Sands drilled 35 round-trippers in the minors in 2010, but his power stroke was dormant until the final week of AFL action. That might be in part because the Blue asked him to work on his ability to go the other way. The 23-year-old is a potential deep, deep sleeper, especially if LA moves James Loney.
• Josh Vitters (Chicago Cubs) can hit but still swings at just about everything. It'll probably be a long time before that changes, and even then, can he be the same hitter?

Middle infielders

Charlie Culberson, San Francisco Giants

The probable heir apparent to Freddy Sanchez may not be as good with the mitt but is likely every bit the hitter. (Don't forget, Sanchez won a batting title in 2006.) Culberson, 21, will likely spend most of 2011 advancing up the ladder but could be a part of the big picture in 2012.

• The Milwaukee Brewers' Eric Farris is inconsistent in controlling the strike zone but hit well in the AFL. He has speed to burn (70 steals in 2009) and may prompt the Brewers to part with second baseman Brett Lawrie. Beyond that, it's unclear where Farris fits.
• The Atlanta Braves' Tyler Pastornicky is an overachiever of the highest order. He's great defensively, but he's just an OK hitter. In a couple of years, he could steal 20 to 25 bases in the majors, if he plays enough.

Outfielders

Bryce Harper, Washington Nationals

It seems unfair to be his size (6-foot-3, 225 pounds) and have his pretty, consistent swing and composure at 18 years old. Pretty much everyone agrees that Harper is for real. One raised concern is the effort he puts into his swing, and it's fair to wonder how he'll handle continually growing expectations. Until you hear differently, don't worry about them.

• Mesoraco could arrive soon

  Trayvon Robinson (Los Angeles Dodgers) whiffs too often, but he also draws plenty of walks and has a burgeoning ability to hit for average. That's a big plus when you add his speed. The Dodgers may be tempted to test it later next season, although 2012 is a better bet.
• How much of Marc Krauss' impressive 2010 numbers can be attributed to Cal League inflation? A November surge in the AFL bumped his slugging rate to .524. The Arizona Diamondbacks may give his power bat a look in left at some point next year, but he seems suited to be a DH.

Pitchers

Christopher Carpenter, Chicago Cubs

The Cubs have employed this right-hander, not to be confused with the St. Louis Cardinals' pitcher, as a starter throughout the minors, with modest results. But Carpenter hits triple digits and made 10 AFL appearances in relief. Although his Fall League numbers were unimpressive, there's no doubting his ability. Many scouts believe that his future lies in the bullpen, where he's a potential saves artist. If the North Siders make such a move permanent, he could be helping the big league club by 2012.

Jeremy Jeffress, Milwaukee Brewers

There are no secrets here. Jeffress, 23, is John Axford amplified. That's in both the strikeout (14 in 11 2/3 AFL innings) and walk (12) departments. He touches 100 and, it's clear, belongs in the bullpen. The Brew Crew has to keep him there, and he could win a spot in spring training. Ascent to closer one day is a possibility, but you see his weakness. Oh, one secret: His off-speed offering has turned out pretty nasty, too.

• The Washington Nationals drafted lefty Sammy Solis in the second round this year. The AFL gave him his first real taste of pro ball, and he impressed many scouts. He has three quality pitches with movement and low-90s velocity, and he could move quickly through D.C.'s system next year.
• The Philadelphia Phillies may look to solve some of their bullpen depth concerns internally, beginning with a possibly fast-tracked Justin De Fratus. He's mentioned as a long-term replacement for Brad Lidge. Control does not appear to be a problem for the 23-year-old.
• The Washington Nationals appear to have themselves a couple of high-strikeout setup men in the works. Cole Kimball (more so) and Brad Peacock generated AFL buzz and could easily help at some point next season.
• Josh Collmenter has a deceptive delivery and throws a nasty changeup, which helps him generate K's (30 in 26 2/3 frames in the AFL) despite unimpressive velocity. If he continues to avoid giving up jacks, he could make an impact for the Arizona Diamondbacks in 2011.
• The Pittsburgh Pirates need quality starters. Justin Wilson, a potential sleeper southpaw in a year or two, could waste his opportunity if he doesn't improve his command. It'd be a shame, because he can pile up K's and does keep the ball down pretty well.