1:01 AM ET

This was supposed to be something of a rebuilding year for North Carolina. And despite the Tar Heels' lofty No. 5 ranking entering the week, their 79-75 loss to Wofford on Wednesday showed that they're not the same team that ripped through the NCAA tournament in recent years.

The last couple of seasons, North Carolina had different escape routes on the offensive end. If Marcus Paige wasn't scoring, they had Brice Johnson in the post. Kennedy Meeks and Isaiah Hicks were options down low last season. Justin Jackson could score at all three levels, but especially in the midrange. Joel Berry was an elite point guard.

Roy Williams had myriad options.

This season, the Tar Heels have a much slimmer margin for error -- and their upset loss at the hands of Wofford was further evidence.

It was the Terriers' first win over an AP top-25 team, having entered the game 0-25 in such games. This is a Wofford team that was 4-4 this season against Division I opponents before Wednesday, including a 20-point loss to UNC Asheville.

Regardless of the weapons at Williams' disposal, this was a game North Carolina should have won. But off-nights occur, and unfortunately for the Tar Heels, they don't have the answers they've had in the past. Luke Maye ended up with fine stats (17 points, 14 rebounds), but he started the game 1-for-11 from the field and ended up shooting 4-for-16. Kenny Williams, who has become the primary perimeter shooter for Carolina and hit double figures in 10 of his first 11 games, made three shots from the field.

Berry was very good, especially late, but he didn't get enough help from his supporting cast.

Michigan State and Wofford are two very different teams, but North Carolina's only two losses of the season came to the Spartans and Terriers and there are clear similarities between the two. Both games were Kenny Williams' only two not in double figures. Maye had his two worst shooting games of the season in the two losses (3-for-13 for eight points against Michigan State). Against the Spartans, Berry struggled en route to a seven-point performance -- while Theo Pinson was the lone bright spot. On Wednesday, Berry was a bright spot -- while Pinson scored two points.

This isn't your usual North Carolina team of recent years that throws out multiple veteran big men with five-star pedigrees, along with a couple of future pros on the perimeter. They have three freshman post players -- Garrison Brooks, Sterling Manley and Brandon Huffman -- who have done surprisingly well this season, but they're not at the stage where Roy Williams can draw up a play to just throw them the ball on the block and get a bucket. Pinson is a relative non-shooter and not someone to get his own look off the dribble. Williams is a solid ancillary option who can make shots from the perimeter.

This team revolves around Berry and Maye, and Carolina can't afford either player to go long stretches without scoring.

The Tar Heels got a boost Wednesday with the debut of Cameron Johnson, a graduate transfer from Pittsburgh who missed the first month of the season because of a knee injury. Johnson is 6-foot-8 and shot 41.5 percent from 3-point range last season. He made only one shot against Wofford but scored 10 points in 17 minutes.

Late in the game, North Carolina used a lineup with Johnson and Maye up front, and Berry, Johnson and Pinson on the perimeter. It's clearly the Tar Heels' best offensive grouping, and one Williams probably will use more often moving forward. Johnson isn't going to be someone who goes out and gets 20 points every night, but he's another weapon on the offensive end -- which is exactly what the Tar Heels need right now.

North Carolina isn't going to overwhelm teams the way it has in the past. It's not going to be able to rely on three- and four-year starters at every position. There certainly are worse duos to start a team with than Berry and Maye, but Williams knows he needs top-notch performances from those two on a nightly basis to win in the ACC.

On Wednesday against Wofford, those performances came a little too late. And the Tar Heels simply don't have the margin for error to survive that anymore.