The five that probably have the highest ceiling potential based upon this season are McNamara, Lachey, Graves, Nwankpa and Dunker. While the others could certainly impact their draft ratings, most are guys where you basically know what you are getting.
McNamara would have to stay healthy and tear it up to get some attention. I doubt it will happen, but he could work his way into the late rounds.
Obviously, Lachey could greatly impact his projection coming off the injury.
Graves and Nwankpa underachieved last year. Both have major potential. Graves needs to really commit to S&C and play with more intensity. With Nwankpa, it's more a matter of getting a comfort level and playing without hesitation.
Dunker has all the measurables that the NFL likes but he'll be projected to move inside. He'll have to show that he has improved on technique and the nuances, but there's a lot to work with there.