College basketball fans already know about the top returning players who have already proven themselves and are again poised for big seasons in 2013-14 -- Doug McDermott, Marcus Smart, Aaron Craft, etc.
But every season there are players who make the jump from playing a role to becoming someone who could be a major contributor to their team's success. These guys aren't always the easiest to identify, but after an offseason of talking to coaches, I've come up with a list of the top candidates to have a breakout season. Note that I've excluded incoming freshman from this list, as they belong in their own category.
Here is my ranking of the top 25 breakout players for 2013-14:

1. Montrezl Harrell, PF, Louisville Cardinals
Sophomore, 6-foot-8, 235 pounds
Harrell came off the bench as a freshman, playing limited minutes behind Gorgui Dieng. However, his production was impressive per minute played (5.7 points and 3.6 rebounds in 16 minutes per game). Now he'll get 30-plus minutes per game -- as long as he remains out of foul trouble -- and he should be one of the top rebounders in the country.
Harrell won't be the shot-blocker that Dieng was for Rick Pitino and the Cardinals, but he'll bring more energy and athleticism. He's a guy who plays with reckless abandon and runs the court extremely well. He'll also be terrific in Louisville's press.

2. Yogi Ferrell, PG, Indiana Hoosiers
Sophomore, 6-0, 180