Mike McCarthy admitted it.  With Aaron Rodgers given the day off from practice as a precaution after complaining of a slight foot sprain, rookie wide receiver Randall Cobb hobbling off halfway through when getting his sprained knee whacked again, as James Jones felt a pain running a deep route and called it a day, with Jordy Nelson (knee) and Jermichael Finley (ankle) watching, McCarthy cut practice short by two full periods, about 25 minutes.  McCarthy admitted afterward "we've hit the wall", in camp.  The number of players nursing a variety of minor injuries and in the middle of a short, final week of pre-season, best to shut down the practice snaps and just make sure the ducks are in a row for New Orleans in a mere 10 days.   McCarthy said Rodgers could have practiced but he wanted to side with caution considering he'll play only a series if at all in the exhibition finale against the Chiefs Thursday night.  C.J. Wilson returned to practice for the first time in over two weeks, the first of three players who suffered concussions in camp who was able to get back on the field.  Lawrence Guy and Anthony Levine are still out of commission.  A shells only practice tomorrow morning at 11 will be the final training camp workout open to the public on Ray Nitschke Field.