Zion Williamson's knee injury knocked Duke back and they have to to plan for him not playing, said coach Mike Krzyzewski.
Blue Devils star Williamson was dribbling towards the basket in the first minute of the 88-72 loss to North Carolina on Wednesday when his left shoe ripped, leaving him on the floor holding his leg.
The top prospect in the 2019 NBA Draft headed to the locker room and was unable to return to the action, with Krzyzewski saying afterwards he suffered a knee sprain and there was no timetable for his return.
Krzyzewski acknowledged his team felt the early blow significantly and will be planning for Saturday's meeting with Syracuse as if Williamson will be unable to take part.
"The preparation you would have for the game is obviously based on your players being there," Krzyzewski said.
"It puts everyone in a state of trying to figure it out while you're playing an outstanding team. That's not a good situation.
"I thought our guys really played hard in the first half. We were knocked back after that injury, you could see it.
"We have to come up with a game plan based on Zion not playing and hopefully he'll be back playing some time in the near future."
Fellow Duke freshmen RJ Barrett (33 points) and Cam Reddish (27 points) carried the Blue Devils' offense in Williamson's absence.
"I thought he was just going to put on another of pair of shoes and get out there," said Barrett. "But, to see that he wasn't going to come back was tough.
"You go in, you game plan, get into the game and 36 seconds in one of our key guys goes out. It was tough for us to bounce back from that."
Reddish added: "It obviously set us back a little bit. He's a key player. Losing him hurt. But, we have to learn how to fight when we lose pieces. It was a tough one for us.
"We miss him as a player, but it's not just that. He is also the source of our energy. So, without him on the floor, that energy is missing. We have to be back in the gym, figuring out how to find that energy while he is gone."