Manuel, who suffered a knee sprain in Saturday's win over Cleveland State, will miss 10-14 days. Williams is getting treatment today to try and get ready for Tuesday's 9 p.m. start against the Illini in Greensboro.
"Yesterday [Manuel] had a brace on it, and he said it felt better," Williams said during Monday's press conference. "But he's definitely not going to play tomorrow night, and we'll have to wait and see until the end of the week how it progresses.
"We're hoping to have Jawad back by tomorrow night, but there is going to have to be some significant improvement from now to then.
"It's a huge problem. We can't stand any of those things that effect our depth."
Adversity has officially set in.
On a team with just 10 scholarship players, three are out – Manuel, David Noel and Damion Grant, and one is questionable – Williams.
"You see it," UNC center Sean May said. "In our last two games, (Williams) has been our leading scorer. He puts points on the board and he's our leader. Now Jackie's out, and that's a big chunk of our team gone. But when it comes down to it, I think Jawad will be in there tomorrow night."
With Manuel out, and Williams either out or, if he plays, less than 100-percent effective, Carolina will have a tall task handling an Illinois team that features size across the front and an excellent guard tandem in the backcourt.
"We worry about Illinois' depth," Williams said. "[Nick] Smith and [Roger] Powell can rebound the basketball. If we do have Jawad, we're pretty sure he's not going to be at full strength. Our guys will have to do their best job of boxing out they have all year if we're going to have a chance.
"With [Deron] Williams and Dee Brown, that is about as quick and heady as you can get. If they're not the best backcourt tandem in the country, they're right up there."
The Tar Heels will need to get more quality minutes from freshman Reyshawn Terry, who scored six points, pulled down three rebounds and added a one assist, one block and one steal in 11 minutes versus the Vikings. Terry looked exceptionally good in his first appearance on Saturday, but then seemed to force it a bit when he was inserted into the lineup later.
"[Terry] had some moments in each direction," Williams said. "When you drive from the top of the key late in the game and turn it over, you don't want to do that. But I've got to like him and he has got to be a positive for us. That's the way I'm going to look at it."
The Illini are led by first-year coach Bruce Weber, a beneficiary of the falling dominos that were created by Roy Williams' off-season departure from Kansas to North Carolina. Weber took over for Bill Self, who took the head job with the Jayhawks following Williams' move.
"Bruce is a good guy," Williams said. "Over the years I've tried to help Bruce down the line. He's deserving of the job at Illinois."
On Dec. 3, 2002, No. 25 Illinois routed then 12th-ranked UNC in Champaign, 92-65. Brian Cook scored a game-high 22 points with eight rebounds and Sean Harrington came off the bench to nail six 3-pointers and finish with 20 points and five steals, as Illinois went on a 25-6 run to close the game. Cook and Harrington have both graduated. Sean May led UNC with 21 points.
The Tar Heels are 100-26 all-time in Greensboro and have won 10 of their last 11 when playing there.