Duke coach Mike Krzyzewski did the rest of the Atlantic Coast Conference a favor when he suspended Grayson Allen last week for his third tripping incident in the past two seasons.

Allen, a 6-foot-5 junior guard, is the latest Blue Devils player we all love to hate, going all the way back to Christian Laettner. The Player of the Year candidate stuck his leg out and intentionally tripped an Elon player in a victory Dec. 21. Not the worst thing in the world.

But it also happened twice without penalty. This time, Krzyzewski suspended Allen indefinitely the following day. After reviewing video, the Hall of Fame coach also saw Allen's outburst on the bench. He couldn't control his emotions.

Now Duke opens conference play without its best player — and it is uncertain when he will return. "The incident was unacceptable and inexcusable," Krzyzewski said in a statement.

That was one of the biggest story lines in nonconference play, simply because of its bizarre nature. But the ACC saw a second blue-blood program receive negative attention the same day.

North Carolina released a third notice of allegations from the NCAA in connection with an academic fraud scandal first filed in 2015. Football and men's basketball were once cleared of potential penalties, but now they are under the microscope again.

Tar Heels coach Roy Williams showed his frustration, telling reporters after a victory against Northern Iowa Dec. 21: "I'm tired of this junk. … I'd hoped the NCAA thing would be over before I retired, and now I'm hoping that it will be over before I die."

Duke and North Carolina have historically been the ACC's bread and butter. They aren't squeaky clean. But neither is the conference's next-best team, Louisville, rocked by scandal of its own last year when reports surfaced of sex parties for recruits paid by a member of Rick Pitino's staff.

Somehow, all of this bad publicity gets overshadowed, though, because we're dealing with Hall of Fame coaches in the nation's top conference for men's basketball. Six ACC teams are in the Associated Press Top 25: Duke (No. 5), Louisville (6), North Carolina (9), Virginia (12), Florida State (20) and Notre Dame (24).

Virginia already upset Louisville on Wednesday, but the Cavaliers will be tested again Saturday against Florida State. Duke and UNC don't meet until Feb. 9 in Durham, N.C., but before then, the Blue Devils have a chance to show their impressive depth playing without Allen on Saturday at Virginia Tech.

The Cameron Crazies might get to see Allen in action once the Blue Devils play their ACC home opener Jan. 4 vs. Georgia Tech. Sure, Coach K is sending a message suspending his All-America and not putting a timetable on Allen's return. But if anyone can afford to lose its best player for a stretch, it's Duke.

Player To Watch

Josh Hart, G/F, Villanova

The 6-6 senior is averaging 20.4 points for the No. 1 team, putting himself at the top of the Player of the Year discussion. When it's a big game, Hart rises to the occasion, most notably in a 37-point performance against Notre Dame. Will he do the same Saturday vs. Creighton?

Game of the Weekend

(1) Villanova at (10) Creighton

Noon Saturday, FS1: Two unbeatens face off in a game with Big East title implications. Several Wildcats players are back from last year's championship team, including Hart. The Blue Jays are surprisingly building a contender, led by Marcus Foster and Maurice Watson Jr.

Final Thought

Are the Hoosiers for real?

Never did I imagine rethinking my pick for Big Ten champion after the opening week of conference play. But Indiana's home loss to lowly Nebraska to open conference play makes me question my belief in the Hoosiers. They can win me over again by taking down Louisville on Saturday.

Big Ten Power RANKINGS

Marcus Fuller's rankings, with five teams to watch:

1. Wisconsin (12-2, 1-0)

The Badgers were the preseason favorites to win the Big Ten, and they have done nothing to cause doubt. Their losses are to Creighton and North Carolina, both top-10 teams. Nigel Hayes is averaging 17.7 points over the past six games.

2. Purdue (12-2, 1-0)

3. Indiana (10-3, 0-1)

4. Maryland (13-1, 1-0)

5. Michigan (10-3, 0-0)

Defensive questions: The Wolverines have some of the most misleading defensive statistics in the Big Ten. They rank second in the league in scoring defense (60.8), but they are the worst in field-goal percentage defense (44.1). The latter reveals more about Michigan's issues on D.

6. Michigan State (10-5, 2-0)

7. Minnesota (12-2, 0-1)

Road woes: The Gophers lost their only true road game in nonconference play at Florida State. Now coach Richard Pitino's team plays four of the next five away from home. Pitino's Big Ten road record is 4-23, including 0-9 last season.

8. Northwestern (12-3, 1-1)

9. Ohio State (10-3, 0-0)

Center of attention: One of the biggest holes for the Buckeyes heading into the season was at center. Trevor Thompson has more than filled that need. The 7-foot junior is averaging 10.7 points, 9.2 rebounds and 1.8 blocks ­— all career highs.

10. Illinois (10-4, 0-1)

11. Rutgers (11-3, 0-1)

12. Nebraska (7-6, 1-0)

13. Iowa (8-6, 0-1)

14. Penn State (8-6, 0-1)

Disappointing start: Several preseason publications picked the Nittany Lions as the surprise team. Will they live up to the hype? They already have lost to Albany and George Mason.

Marcus Fuller covers college basketball for the Star Tribune. marcus.fuller@startribune.com