Kelvin Sheppard out couple days

PITTSFORD, N.Y. -- Buffalo Bills starting middle linebacker Kelvin Sheppard missed practice because of what coach Chan Gailey only would call a medical issue.

Without revealing what the issue is, Gailey on Wednesday said he expects Sheppard to miss a couple of days of training camp. Sheppard watched the team's night practice from the sideline.

Starting defensive tackle Marcell Dareus was held out of the final hour of practice as a precaution after the player complained of tightness in his leg.

Receiver David Nelson missed his third straight practice since straining a ligament in his right knee on Saturday. Nelson continues to work individually and could be cleared to return before the end of the week.