Duke's issues without Ryan Kelly

Ryan Kelly's defense and 3-point shooting will be sorely missed while he's out. Lance King/Getty Images

After injuring his right foot, Ryan Kelly sat out the second half of Duke's comfortable 68-40 win at home against Clemson. Playing without Kelly, the No. 1-ranked Blue Devils posted their worst defensive showing of the season four days later, allowing host NC State to score 1.17 points per possession in Duke's 84-76 loss -- its first of the season.

Cause and effect? Not entirely, of course, but to a certain extent, one thing did help the other along. Kelly's absence didn't single-handedly trigger the Blue Devils' first loss, but it sure didn't help. More importantly, there's good reason for Mike Krzyzewski to be worried as long as the 6-foot-11 senior is sidelined by his injury.