With the end of the minor league regular season arriving, it's time to start wrapping up 2010. Instead of a traditional All-Star team, here are the players at each position that for one reason or another exceeded the most expectations. One additional caveat, all the players listed here are pure prospects that have yet to taste the nice hotels and big per diems of the big leagues.

Catcher: Devin Mesoraco, Reds
At the start of the year, many thought Mesoraco had entered into bust territory. A first-round pick in 2007, Mesoraco began the year with career averages of .240/.311/.368 and scouting reports that bemoaned a lack of conditioning. This spring, he showed up in camp looking more like a linebacker than a baseball player, and the results were clear, as he slugged a whopping .302/.377/.587 across three levels, and scouts believe in the transformation. Suddenly on the brink of the big leagues, Mesoraco is yet another reason to be optimistic about the Reds' short-term and long-term future.

First Base: Brandon Belt, Giants
A fifth-round pick in last year's draft, Belt entered the year with the reputation of a good hitter without enough power to be an everyday first baseman in the big leagues. The Giants' coaching staff made two changes to his setup in the spring, closing his stance and lowering his hands a bit. The differences took nothing away from his skill to put a bat on a ball while adding the abilities to use all fields and drive to his pull side. The end result was the breakout of the year, as Belt began the year in the California League and finished in Triple-A, mashing at every level to finish with one of the best composite lines in the minor leagues at .352/.455/.620. His timetable has shrunk significantly, and the Giants have gone from trying to change his stance, to wondering how soon they'll need to find him some big-league at-bats.

Second Base: Jean Segura, Angels
Toiling in the shadows of Mike Trout before the electric outfielder moved up to High-A, Segura emerged in the second half to become the Midwest League's most exciting player. A plus-plus runner with a good approach and the rare (and much desired) combination of contact skills and the ability to drive a ball, the 20-year-old Dominican hit .338/.390/.545 during the second half of the season, and could end up putting some monster totals in the Southern Division of the California League next year.

Third Base: Mike Moustakas, Royals
The second overall pick in 2007, Moustakas went from mild disappointment to one of the top hitting prospects in the minors. He tied for the overall lead with 36 home runs while hitting .322/.369/.630 across Kansas City's two upper-level affiliates. He draws some criticism for a free-swinging approach, but a lack of walks is mitigated by the fact that he's hardly a one-dimensional slugger, as the third baseman who turned 22 over the weekend struck out just 67 times in 484 at-bats. He's not a power hitter as much as he's a hitter with power, thanks in part to the fastest bat in the minor leagues.

Shortstop: Grant Green, Athletics
Shortstop had numerous candidates, including Seattle's Nick Franklin, who shocked everyone by leading the Midwest League with 23 home runs. Still, Green outhit him by a wide margin with an explosive second half that had many observers wondering what he was still doing in the California League. Green hit just two home runs in his first 56 games for High-A Stockton. Then the 2009 first-rounder hit 18 homers in his last 75 games to finish the year with a .318/.363/.520 line that included 65 extra-base hits. Unfortunately, with all of the offensive answers came a new round of defensive questions, as some disturbing difficulties with even the most basic of throws led to 37 errors in just 114 games at shortstop.

Left Field: Jerry Sands, Dodgers
A 25th-round pick in 2008 out of Division II Catawba College in North Carolina, Sands proved to have plus-plus raw power in the short-season leagues. However, a monstrous .333/.432/.646 line during the first half of the season at Low-A Great Lakes didn't lead to a big move up prospect charts, as many saw him as a 22-year-old beating up much younger talent. A two-level jump to Double-A changed everything, as Sands continued to impress with a .270/.360/.529 line that included 17 home runs in 68 Southern League games. While Sands is actually a good athlete for his size, he's yet to find a defensive home, as his outfield play is rough and he could be limited to first base in the end. No matter where he ends up, he's one of the few prospects in the Dodgers' system that could fit in the middle of a big-league lineup.

Center Field: Mike Trout, Angels
The 25th overall pick in the 2009 draft, Trout entered the year as a toolsy athlete with promise, and ended it as one of the best prospects in all of baseball while hitting .341/.428/.490 across the Angels' two A-level affiliates. It's not the pure hitting ability as much as it's the big league-ready approach. It's not the game-changing speed as much as his ability to already make use of it in the field and on the basepaths. And there's the infectious energy and the sub-4.0 speeds to first base on even the most routine of ground balls and doing so with a smile on his face the entire time. Not only was he the best prospect I saw all year, he might also have been the one who was seeming to have the most fun, and extreme talent and off-the-charts makeup is the kind of equation that often results in superstardom.

Right Field: J.D. Martinez, Astros
To say Martinez came out of nowhere doesn't really do his season justice. A 20th-round pick last year out of Nova Southeastern, a small D-II school in Florida, Martinez was on nobody's radar entering the year, but his .362/.443/.598 line earned South Atlantic League MVP honors despite the fact that he lasted just 88 games at Low-A. That at least drew scouts' attention, but it was the .302 batting average in 50 Double-A games that started to generate some true believers. He's not much of an athlete, and there are still plenty of questions about his ability to produce the kind of power generally associated with corner outfielders, but he sure can hit, and the Astros system is desperate for any player fitting that description.

Starting Pitcher: Julio Teheran, Braves
Nearly every team has this kind of pitcher; the big bucks teenager with the lightning arm, all the promise in the world, and precious little track record. Teheran began the year at Low-A, and finished it two levels higher, limiting the advanced hitters of the Southern League to a .204 batting average as a 19-year-old. When Stephen Strasburg moved up to the big leagues, many felt that Teheran made the leap from the arm you can dream on all day to the best pitching prospect in the game.

Relief Pitcher: Donnie Joseph, Reds
A third-round pick last year out of the University of Houston, Joseph was seen as one of those college relievers who could move quickly, and he didn't disappoint. He traveled across three levels in the Cincinnati system, finished the year at Double-A, and struck out 103 over just 65 innings in the process. He doesn't throw anywhere near as hard as Aroldis Chapman, but his 93-95 mph heat is plenty for a lefty, and the key to his success for many is a slider than went from solid to downright filthy. If the Reds do the right thing and return Chapman to starting for his long-term development, they'll still have a power southpaw out of the bullpen in Joseph.

A version of this story originally appeared on ESPN Insider Insider.

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Really enjoy these articles that help us put a player's performance into an organizational context.
Fantastic article! No doubt I will be referencing this article many times before the start of next season. Great work, Kevin.
Are scouts sold on Mesoraco's defensive skills? The Reds already have one blocked prospect at 1b, and one OF corner filled for the future (Bruce), so if he's not really a catcher (like so many "catching prospects") does this cloud his future?
He's hands are a little hard back there, but he moves well and a has a quick release on the throws. He's not a Molina, but he's certainly good enough to stay there.
Was Mesoraco more of a surprise than Arencibia?
Arencibia is in the big leagues . . .
I thought they opened up Belt's stance, rather than closed it.
Any sentiment for Jason Kipnis at 2B? I'll concede Segura's great year, but Kipnis is arguably the best OF-turned-2B out of the 2009 draft so far.
The mention of an Astros prospect in an article such as this makes me weep for joy after 8,982,374,982,347,928,347 Astro-free "Future Shock"s this season. That's a slam on the 'stros, not on you. Thanks for the great read this season, your column is a real highlight here.
Jeez, I hope Trout isn't reading this and letting it get to his head.