Kentucky's pursuit of perfection has taken a major hit ahead of another tough test on the top-ranked Wildcats' nonconference schedule.
The Wildcats learned they will be without Alex Poythress for the rest of the season one day before facing No. 21 North Carolina on Saturday.
On a team loaded with talented underclassmen, Poythress was providing veteran leadership for coach John Calipari, but the junior tore the anterior cruciate ligament in his left knee during practice Thursday and will undergo season-ending surgery.
He started all eight games he appeared in, averaging 20.3 minutes, 5.5 points and 3.8 rebounds. The 6-foot-8 forward's athleticism and size had the biggest impact on defense and he ranked third on the team with 1.5 blocks per game.
"Things that people can't do, he could do. And they all came at great times," Calipari said of Poythress, who has played in a team-high 81 games since the start of 2012-13.
"Now we're different. You don't have that guy you can play poorly and he will go do something to get you back in the game."
Poythress and the Wildcats had rolled through the early part of the season, winning all 10 games by double-digits, including a 56-46 victory over Columbia on Wednesday.
Kentucky will now be forced to alter its system, which featured a starting five of Poythress, Aaron Harrison, Andrew Harrison, Karl-Anthony Towns and Willie Cauley-Stein. That unit has accounted for 60 of the team's 86 blocks and 409 of its 754 points.
The good news for the Wildcats is that their production is very even up and down the roster, with only one player - junior Willie Cauley-Stein - averaging double digits in points and none logging more than 24.1 minutes per game.
"I told you there's going to be some ups and downs," Calipari said. "We'll probably get dinged some. I hope not Saturday, but it could be Saturday."
North Carolina hasn't experienced quite the same success as Kentucky, but the Tar Heels (6-2) may be able to use forwards Brice Johnson and Kennedy Meeks to capitalize on the Wildcats' suddenly weakened frontcourt.
Johnson, who averages 11.3 points, had a career-high 17 rebounds Sunday in a 108-64 win over East Carolina after a lackluster two-point effort in a Dec. 3 loss to Iowa.
"I challenged him," coach Roy Williams said Sunday. "There's no question about that. ... I got ticked off at him the last three days, and he was really good today."
Meeks has performed more consistently for UNC, posting his sixth double-digit rebounding game Sunday and ranking among national leaders with an average of 10.1.
Marcus Paige could give the Tar Heels a boost against Kentucky, just as he did in last year's matchup when he scored a game-high 23 points to help lift North Carolina to an 82-77 win on Dec. 14 in Chapel Hill.
That sort of production, however, has been curiously absent from Paige's game this season. The preseason All-American is averaging career worsts in rebounds (1.5) and assists (3.4), while his scoring average has dipped from 17.5 last season to 14.0.
"We've got to play the best game we've played all year, there's no question about that," Williams said. "We need to make some outside shots to open things up for us inside. We need to play without turning the ball over carelessly. We've got to have our best rebounding game of the year. And we've got to hope they miss some shots."
This matchup could turn into a defensive struggle considering both Kentucky (28.7) and North Carolina (33.5) sit among the nation's top five in opposing field-goal percentage. The Wildcats rank No. 1 at 45.8 points allowed per game.
North Carolina has beaten the top-ranked team 13 times in program history, most recently Michigan State on Dec. 4, 2013.
The Tar Heels are 23-13 all-time against Kentucky.