Ben Revere - Revere has shown exactly what was expected of him. His speed gives him great outfield range and he uses it well to steal bases. He has a very weak arm and no power. He hasn't hit that well, but given his minor league numbers, that probably won't continue. As he matures he may add some gap power, but he's not likely to develop into the next Kirby Puckett. Although it is helpful to remember that, as a rookie, Puckett didn't display much more power than Revere and he was a year older than Revere. Revere is probably a lock to start in left field next year, although its possible Gardenhire will stick him in center field with Span moving to a corner spot. He will likely bat ninth to start the season with Casilla returning to the number two spot.
Chris Parmelee - Parmelee is demonstrating what made him a first round choice. He is a smart hitter with good bat speed and he will likely develop power as he matures. He has work to do on his defense at first base. He could step into a major league role next year depending on Morneau's health and who the Twins sign in the offseason. If Morneau and Mauer are going to fill the DH role more often, Parmelee may have a job as the backup. My guess is that is something the Twins will be mulling over this winter.
Trevor Plouffe - Plouffe's power outburst has demonstrated why he has been a top prospect despite his often mediocre minor league numbers. Unfortunately his erratic defense has demonstrated why he has been kept in the minor leagues. With the Twins problems in the middle infield, he is likely to get a shot at winning the starting shortstop or second base spot. But it sounds like Gardenhire has figured out that he needs solid defense for his pitching to succeed. That means Plouffe's bat can't be allowed to make up for his defensive deficiencies. If the Twins fail to sign either Kubel or Cuddyer, he could end up in a corner outfield spot. I am not sure his bat contributes enough to make him more than a mediocre corner outfielder. The other option is third base, but that depends on the Twins evaluation of Danny Valencia.
Luke Hughes - Hughes is a player without a position. By default his best position is probably first base. But he doesn't have the bat to play their regularly. He can also play second and third, but his defense doesn't make him acceptable as a regular at either position. What Hughes has going for him is his right handed bat and his flexibility. That may be enough to land him a bench spot next year. But he will have to hit better to not end up back at AAA.
Rene Tosoni - Tosoni has not shown very good results, but he has shown some potential. He is an adequate defensive outfielder, but at 25 he doesn't have much more time to develop his bat and contribute at the major league level. As a lefty, his chances of contributing next year probably depend on who the Twins sign in the offseason. If Kubel returns, the competition for left handed at bats probably leaves Tosoni back at AAA.
Tsuyoshi Nishioka - Nishioka has obviously been a huge disappointment this year. But given the money he is being paid, he will likely have a roster spot next year. He will compete for a middle infield spot in spring training and likely end up as a utility player at worst. There is always the possibility that with a year to adjust he will still contribute. But its also possible the Twins will decide to cut their losses and release him.
Brian Dinkelman - Dinkelman demonstrates why versatility sometimes wins you a major league job. Like Hughes, Dinkelman doesn't really have a position. He can play the outfield and second base, but not all that well. He isn't going to compete for a regular position and his left handed bat make him less desirable on the bench than Hughes. He is a quintessential AAAA player.
Joe Benson - Benson demonstrates why athleticism is over-rated in baseball. He has good speed, power and arm strength. Unfortunately, he can't consistently make contact. His rookie mental mistakes add to the impression of a player with physical tools who hasn't developed his baseball smarts yet. Benson is the same age as Parmelee and Revere, but way behind them on the development curve. It looks unlikely Benson will be ready to help next spring. That said, power hitters often take a while to develop. If he can learn to deal with breaking pitches and cut down his strikeouts, Benson is a starting major league outfielder. But there are a lot of good athletes who never figure that out.
I will do a similar evaluation of the young pitchers in a later post.