ESPN Men's Basketball

CHAPEL HILL, N.C. (AP) -- North Carolina's Roy Williams knew what last year's team could accomplish before the season. The Hall of Fame coach has more questions than answers this time.

"Last year we were picked first (in the Atlantic Coast Conference) and I thought that was fine because I thought we could be the best team," Williams said. "I don't have any idea what the ceiling could be for this team. And I don't think we'll know until we get into conference play."

The 11th-ranked Tar Heels (32-6) open their season at home Friday night against Gardner-Webb and must replace NBA first-round draft picks Harrison Barnes, John Henson, Kendall Marshall and Tyler Zeller from a preseason No. 1 that went on to win the ACC regular-season title and reach an NCAA regional final.

Left behind is a forward who struggled most of his rookie season before coming on late, a veteran guard, two players returning from serious knee injuries and several youngsters stepping into significant roles. That means UNC, picked to finish third in the league, will have less room for error.

"We won games last year when we didn't play great," Williams said. "This year, we've got to play closer to our potential or we're not going to be successful."

It has been a bumpy offseason for the Tar Heels. After the NBA defections, they lost longtime assistant Jerod Haase, who became head coach at UAB.

Then, a month before practice started, the 62-year-old Williams had surgery to remove a tumor from his right kidney. Tests eventually determined it was a benign growth -- as was a similar one on his left kidney -- but Williams has had to go easy during the first several weeks of practice as he recovered.

Now they're preparing to find out if sophomore James Michael McAdoo is ready to pick up where he left off late last season.

McAdoo, a 6-foot-9 forward, often looked lost through his freshman season as a reserve. But he averaged about 11 points and five rebounds in the ACC and NCAA tournaments when pressed into more minutes due to Henson's wrist injury.

The former McDonald's All-American is a preseason all-ACC pick entering the year. He's the closest thing the Tar Heels have to a proven frontcourt presence.

"I know there were certain things I just had to realize I had to do, and that's focus in each and every day in practice," McAdoo said. "Practice makes perfect but perfect practices help even more. I think that's something I had to work on. It's not something that just all of a sudden clicked. It's something I really started to work on at practice in late January or early February, but it didn't show up until late March."

Junior guard Reggie Bullock also returns to provide outside shooting and long-armed perimeter defense, while he's joined by two guards -- Leslie McDonald and Dexter Strickland -- returning from torn knee ligaments.

McDonald, the team's best outside shooter in 2011, redshirted last season after he was hurt during a summer-league game. While McDonald has had more than a year to recover, Strickland was injured in January and is still working his way back to full strength.

If both players return to form -- Strickland was the team's No. 2 ballhandler and best perimeter defender -- the Tar Heels will have three veterans in the backcourt along with the return of sophomore guard P.J. Hairston.

"With Kendall, Harrison, John and Z leaving, that's the majority of the points," Hairston said. "It's up to us, the upperclassmen and the freshmen that just came in to step up. If we step up and do everything we're supposed to do, it can be a good season and we can do anything we want to do."

Replacing Marshall at the point, however, will be the toughest challenge, one that will likely fall to freshman Marcus Paige. The 6-foot, 157-pound lefty is a McDonald's All-American, and Williams has said he expects Paige would have the first shot at the starting job.

Freshman forward Joel James (6-10, 260) could provide some needed bulk up front alongside McAdoo, while the Tar Heels also brought in 6-9 forward Brice Johnson and 6-5 wing J.P. Tokoto.

The pieces are there for another strong season. And after his recent health scare, Williams is going to enjoy putting the puzzle together.

"I really want to enjoy the journey a heck of a lot more myself," Williams said. "I preach that every year to my kids and particularly the fans as well. My wife tells me I always do the worst job of it, but I'm really going to try and do a much better job of that myself."

North Carolina has won seven straight openers and captured its three meetings with Gardner-Webb by an average of 25.7 points.

The Runnin' Bulldogs are seeking their first winning season in seven campaigns. Third-year coach Chris Holtmann has his top two scorers from last year's 12-20 team back in guards Tashan Newsome (12.3) and Max Landis (9.5).

Friday will mark the Gardner-Webb debut of Jarvis Davis, who is eligible after transferring from Central Florida. Davis is expected to be one of the team's top newcomers.