The sixth-ranked Blue Devils will be without Kelly for the entire tournament as they chase a fourth straight title beginning Friday night in Atlanta against Virginia Tech.
Kelly sprained his right foot Tuesday during practice and will be re-evaluated March 12. The 6-foot-11 junior averages 11.8 points and 5.4 rebounds.
Krzyzewski, in search of his 14th ACC tournament title, isn't necessarily worried about playing three games in three days.
"You've got to plan like you're playing the one game, play 'em one at a time," Krzyzewski said.
These teams met in the semifinals last year in their lone previous ACC tournament matchup, with Duke (26-5) winning 77-63. The Blue Devils haven't lost in this event since a 78-74 semifinal defeat to Clemson in 2008.
"It really doesn't matter who we play," Krzyzewski said. "The road to a championship is going to be a difficult one because it will start off with a real tough game and if you're fortunate to go to Saturday and Sunday, we've got a chance to play the top teams in the conference."
While Krzyzewski isn't looking past Virginia Tech (16-16), his players have their eyes set on a possible meeting with No. 4 North Carolina in the championship game after the Tar Heels captured the regular-season title with an 88-70 win last Saturday in Durham.
"Hopefully, we'll win our first two games, and I hope we see Carolina again," guard Seth Curry said. "Go in there and try to win the championship. You want to put a banner up. That's your goal coming into the season, and we didn't do that in the regular season, so hopefully we can do that in the postseason."
Duke's Austin Rivers was named ACC rookie of the year after leading all conference freshmen with a team-best 15.3 scoring average.
"Individual awards are great but at the same time we are all focused on winning championships as a team and that is what I want to win," Rivers said.
Rivers averaged 20.5 points on 52.2 percent shooting in two wins over the Hokies this season. Virginia Tech was led in those games by Erick Green, who averaged 16.5 points despite 41.9 percent shooting.
"What I kind of always tell our guys that first and foremost when you play Duke, you've got to understand that they're going to draw a line in the sand each and every play," Virginia Tech coach Seth Greenberg said. "You've got to match their competitive spirit before you can even worry about playing basketball."
Green scored 24 points as Virginia Tech ended a four-game losing streak with Thursday's 68-63 win over Clemson. Dorenzo Hudson added 19 points - his highest total since a 31-point effort Nov. 15.
"The leadership they showed and the resiliency they showed and the belief they showed in each other and their teammates was really fun to watch," Greenberg said. "They showed that toughness that is Virginia Tech basketball."