DURHAM — Some time in the first half — Duke coach Mike Krzyzewski isn’t sure when — Ryan Kelly hurt his right foot. That’s the same foot he sprained during the Blue Devils’ December holiday break, and it’s the same foot that caused him to miss the ACC and NCAA tournaments. He did not play in the second half.

Kelly had surgery on that foot last March and said he was completely healed at the beginning of the season. Krzyzewski didn’t know the extent of the injury after Duke’s 64-40 win against Clemson and said Kelly would have a CAT scan and X-rays Wednesday.

“We’re hopeful that it’s not real serious,” Krzyzewski said. “But for precautionary reasons, we felt that it wasn’t good to play him in the second half.”

Kelly came out of the locker room a few seconds after the second half started, and he went to the locker room before the end of the game. He stood up and walked in and out of huddles during the second half and didn’t give any outward signs of pain.

Starting strong: Over the past six games, a trend has emerged: Duke doesn’t start off games strong, or at least as strong as members of the media would like. Despite having a 41-30 lead against Wake Forest and a 25-10 lead over Clemson after 20 minutes of play, the players continue to field questions about what is wrong with the Blue Devils at the beginning of the game.

“It’s hard to come out in the beginning of the game and just blow a team out, even if you’re better than them,” Seth Curry said. “They come out with a lot of energy, and it’s hard to just come out and go on a 15-0 run. You’ve just got to play the game, and they’ll wear down eventually.”

Against the Tigers, Duke shot a season-worst 29 percent from the field in the first half. But Clemson started even worse, hitting just 3-of-25 (12 percent) from the floor. Duke did take solace in its defensive performance in that half.

“I know people will talk about how our offense was stagnant or we didn’t score in the first half, but our defense was great,” Plumlee said.

Playful push: Mason Plumlee was more animated than normal on the floor against Clemson. With 5 minutes, 21 seconds left in the first half, Plumlee lunged toward the basket on an ill-advised dunk. Alex Murphy grabbed the offensive rebound and converted the putback despite being fouled by K.J. McDaniels. Plumlee was fired up, as he grabbed Murphy from behind and then gave him a shove in celebration.

“To come in and get an and-one, in a game where they aren’t calling much, that was a physical game, he came in and did a lot of good things,” Plumlee said. “It was fun to play with.”

In the second half, Plumlee almost pushed Amile Jefferson into the row of photographers along the baseline after he, too, converted a tough shot around the basket.

“He made a big play, too,” Plumlee said. “Got to share the love.”

Keeley 919-829-4556; Twitter @laurakeeley