Any high draft pick with tantalizing upside. Hunter and Patterson are obvious candidates. Maybe Austin too if you're a believer.
I expect better numbers from Eifert. If Lynch misses time (I'm still uncertain about whether or not he's facing a suspension), Christine Michael could wow people in spot duty.
the three WRs came to mind for me immediately.
if usage was an issue more than intrinsic talent, upside is massive, given the flashes they have shown. increased usage should lead to imminent production increases by next season. this usage issue is most obvious in the case of patterson and hunter, though i think austin was both misused and underused.
i wouldn't call bernard disappointing, exactly, but he is capable of much better if used more, top 5-10 numbers soon. bell was delayed and played through injury, and the team really wasn't that good. if they get better, over a full 16 games (he didn't have history of injury at michigan state, but forget if he had one big season?), i think he could be in the top 10-12 conversation as RB1. montee ball had a breakout game recently. if he supplants moreno at some point (most expect DEN to retain moreno? not sure if a consensus), may not be in 2014, but if/when he does, his value will surge.
* Definitely Eifert, assuming Dalton doesn't lock in too much on AJ green (and especially if gresham moves on no later than 2015, i don't think he is a free agenct next year, so it could be a few year process and dynasty owners will need to be patient, which they should be inclined to do anyways given what they probably paid, especially in TE premium scoring leagues which are becoming increasingly popular) - he has blue chip, elite talent, and when he gets a little stronger, could be a difference maker and top 3-5 scoring monster at the position.
Manuel seems to have more obvious upside at QB than Geno (improvement in the form of greater consistency essential by next year, or imo he doesn't get a third year... the clock is ticking faster and the organization could be more restless and impatient after waiting too long on sanchez to eventually develop - they also could soon have one of the best DLs in the NFL, and a more consistent and possibly experienced QB could be the only thing that stands between the team and their playoff hopes and aspirations), and Glennon may if TB doesn't get an obvious starting QB in free agency or the 2014 draft.
IDP...
DE - 1.3 Jordan and 1.5 Ansah.
LB - Ogletree is going to get better, and could be a fixture in top 20 LBs, with upside. Aarthur Brown was a huge disappointment, and many will forget about him. he is talented if he is given a larger role, Daryl Smith won't play forever.
Safety - mid-first rounders Vaccaro and Reid and 2.1 Cyprien are the real deal. imo, 1.32 Elam has upside, as does STL third round SS Mcdonald