Tracy McGrady joins The Jump to reiterate his point that Zion Williamson should sit out the remainder of the season after he suffered a knee injury vs. UNC. (1:43)

Duke coach Mike Krzyzewski is optimistic about Zion Williamson's health after his star player suffered a grade 1 sprain to his right knee in Wednesday night's loss to North Carolina.

The Blue Devils said Williamson, the consensus top-ranked prospect for June's NBA draft, is "day-to-day" after leaving the top-10 showdown in the first minute, and Krzyzewski wasn't able to estimate when he will be healthy enough to play again.

"I think that everyone wants to know his status, and it's still -- we don't have a timetable, but the preliminary reports that we have on Zion's injury are all optimistic -- very, very good," Krzyzewski said on his weekly show on ESPNU Radio on SiriusXM. "And the fact that it's a stable condition, a mild sprain, and we're going to do what everyone would do, and that's what's in the best interest of the young man. And Zion will get proper care. He's getting it today, as this moves along these next 24, 48 hours, we'll have a better feel for things, but there's no rush. You want to make sure he's completely at 100 percent."

Williamson grabbed his right knee in pain after slipping awkwardly and falling when his left shoe fell apart as he planted hard while dribbling near the free throw line on the opening play of the game. The blue rubber sole ripped loose from the white shoe from the heel to the toes along the outside edge, with Williamson's foot coming all the way through the large gap.

He walked off with a slight limp but under his own power before heading back to the locker room with no shoes on his feet.

The top-ranked Blue Devils (23-3) looked lost without Williamson and lost 88-72 to the Tar Heels. Duke has five games remaining -- including a regular-season finale at UNC on March 9 -- ahead of the ACC and NCAA tournaments.

"We know we're an NCAA [tournament] team," Krzyzewski said Thursday. "We've won 23 games with great competition, and we're going to keep moving on, but we want to be -- want to make sure we're at 100 percent when we enter that one-and-done period called March Madness."

Williamson's injury led some NBA players to criticize the NCAA and voicing their opinion on whether Williamson should sit out the rest of this season to prepare for the NBA draft.

"My advice to him is, 'Do what's best for you and your family.' Obviously college ... it does nothing for him at this point," said Golden State Warriors big man DeMarcus Cousins. "You've proven you're the No. 1 pick coming out, you've proven your talent. Get ready for the next level, because it's happening."