And the 10th-ranked Blue Devils don't have a lot of time to fix the problems — not with a date with No. 5 North Carolina looming later this week.
"I've already used five minutes. We're going to stress more than I can talk to you about," Krzyzewski said Monday during his weekly 10-minute segment on the ACC coaches' media teleconference. "The main thing is just to be prepared for playing the best, most talented team in our conference and maybe the most talented team in the country.
"They can be an offensive juggernaut, and especially at home," he added, "and so we have to play really good defense in order to have an opportunity to beat them."
A 78-74 overtime loss to Miami at home on Sunday dropped the Blue Devils (19-4, 6-2) into third place in the ACC, one game behind co-leaders Florida State and North Carolina. They also slipped three spots in the latest national rankings.
That defeat also delivered another blow to Duke's air of invincibility at Cameron Indoor Stadium, where the Blue Devils once won 45 straight games but now have lost two of their last three at home. The only win there in that stretch — a seven-point victory over a St. John's team that's tied for 10th in the 16-team Big East — felt like a loss, Krzyzewski said at the time.
The St. John's win and the Miami defeat shared a few common themes — most noticeably, a lack of energy and effort at inopportune times — that must be fixed if the Blue Devils are to beat the Tar Heels.
"You've got to move on, man, because this game is a big game for us," freshman Austin Rivers said. "We see this as an opportunity to turn what happened (Sunday) back into positive ways.
"If we can get a big win at Carolina, it can turn things around — not like we're going down any bad path. We've been playing great lately, we've just struggled yesterday with that loss. A big win against Carolina can change a lot of things for us."
Duke led the Red Storm by 22 in the second half, only to shift into cruise control down the stretch while St. John's rallied, making it a four-point game late before the Blue Devils held on.
Then against Miami, Duke once again seemed to go through the motions through much of the way, falling behind by 16 early in the second half before rallying to tighten things up. The Blue Devils then missed seven of their final eight free throws, including all six in overtime and one by Rivers with 21 seconds left in regulation that would have put Duke up by one point.
"The first 24 minutes, my feeling is, you can't cheat the game," Krzyzewski said afterward. "You have to play (hard) all the time, and I think free throws go in at the end, at least more often than not."
Defense has been an issue all season. Duke ranks 10th in the ACC with an average of 69.1 points allowed per game — its worst since the 2007-08 team gave up an average of 69.4 points. The Blue Devils allow teams to shoot 43.8 percent — last in the league.
"It's something that we've shown flashes of being good at, and I think it just comes down to being consistent," junior Ryan Kelly said. "It has to be a true decision that we're going to be better defensively, and it has to be there every single day."
They had serious trouble containing Miami's Reggie Johnson, who finished with a career-high 27 points and a season-best 12 rebounds while setting the tone in overtime by scoring his team's first four points. Afterward, Kelly said the Hurricanes' big man "got whatever he wanted around the basket."
That doesn't bode well with North Carolina's elite corps of big men — headlined by senior Tyler Zeller, shot-altering whiz John Henson, versatile sophomore Harrison Barnes and high-energy freshman James Michael McAdoo — that Krzyzewski called "the best front line in college basketball."
In Kelly's locker hangs a list of the team's standards for its big men, and they include winning the rebounding battle, not allowing weak shots and not permitting any uncontested layups.
"We have to meet them every single day," Kelly said. "And if we don't meet them, we think it's somewhat of a failure of a day. To win games, you have to do them."
Krzyzewski says there's enough time left in the regular season to get those things corrected.
"These games, especially in conference, turn out to be like attention to detail, or you have to make a play," Krzyzewski said. The Miami game "still boiled down to, you have to hit a free throw. And so when you win a number of games, sometimes your attention to detail is not where it needs to be. ... That's what we're trying to drive into our guys, the importance of every play, and especially down the stretch."