After getting to spend the season watching the Kernels, there are a number of them that I think should be watched for possible "breakout" seasons in 2014. What exactly constitutes a "breakout" would vary by prospect.
A couple of "off the radar" guys that I don't think got enough credit for the quality seasons they had are Brett Lee and Dalton Hicks. Breakout seasons for them might be merely putting together a second consecutive excellent season as they move up in class.
Jose Berrios and Max Kepler are two guys who are already pretty much "top 10" Twins prospects already, so for them, "breakout" might be having significantly better statistical seasons than what they had in Cedar Rapids in 2013.
But if I were to choose two players, one position and one pitcher, that I would predict to open eyes in 2014, they would be Travis Harrison and Mason Melotakis.
Harrison worked hard at learning 3B last season, but I don't think he ever really felt comfortable over there and as the season went along, I felt like the laboring defensively carried over to his offensive game. He walked a lot, which is good. He also got wrung up looking at third strikes on (and often, just off) the outside corner, which isn't good. I think he was one pretty frustrated ballplayer by year end, but man can he crush a baseball.
If it were me, now that the Twins seem comfortable with Sano playing 3B, I'd put Harrison back out in a corner OF spot and let him play ball. He has good foot speed and a good enough arm. If he's able to concentrate primarily on his hitting for a season, I think he could have a big year in 2014.
Melotakis is one of the college relievers that the Twins are giving a shot to be starting pitchers. He had some success with Cedar Rapids and, while the jury is still out on whether he will end up in a rotation or a bullpen long term, I think it's worth giving him a time in both roles again in 2014. His fastball is very good, but it wasn't until he moved to be bullpen later in the season due to reaching his innings limit that his slider became an effective out pitch. He told me in mid-June that they were still experimenting with new slider and change-up grips at that point.
Melotakis seems like about as laid back a guy as you could imagine off the field, but on the mound he's very competitive and I like that combination. If he makes strides in 2014 with the secondary pitches and one of them can become a legit out-pitch, I think he could climb the prospect list - and the organizational ladder - quickly.