KANSAS CITY, Mo. (TNS) — Nick Collison's mom, Judy, and dad, Dave, summoned their son to a hallway of the Oklahoma City Thunder's Chesapeake Energy Arena after a recent playoff game against the Utah Jazz.

"We have a surprise visitor for you," Judy informed the 37-year-old, 15-year NBA veteran, also the second-leading scorer and third-leading rebounder in University of Kansas basketball history.

The guest, Collison discovered soon enough, was his former college coach, Roy Williams, the current head coach at North Carolina.

"I was sort of hiding behind the corner. He had a big smile on his face. It was really neat," former Jayhawks coach Williams told The Star on Thursday in a phone interview held the day Collison announced his retirement from the NBA.

Williams had a sneaky feeling this season would be the last for the 6-foot-10, 255-pound Collison, and thus made plans to attend the Thunder's playoff contest with current UNC assistant and former KU aide, Steve Robinson.

"We had a 45-minute conversation," Williams said. "He said some great things to me. I tried to tell him how proud I was, but he said some things that made me feel very, very good. I didn't go out there for him to make me feel good," Williams added, laughing, "I went there to try to help make him feel good, to let him know I was still supporting him as much as I possibly could."

Williams _ coincidentally he spent some time with Collison's KU teammate and fellow Iowan Kirk Hinrich just a few days prior to the trip to OKC (Williams accepted Hinrich's invitation to speak at an event in Sioux City) _ on Thursday revealed a little-known fact about Collison, who along with Hinrich helped KU to two Final Fours (2002, 2003).

"I really don't know that I ever yelled at Nick Collison," Williams told The Star. "There's not many players I could say that about. He tried to do everything you asked him to do. If you try to do everything coach says and you do it as hard as you possibly can, there's nothing to yell about. I would say he definitely qualifies as a guy I yelled at the least of any player I coached," Williams continued, noting he "had to yell at Kirk to calm him down sometimes."

Collison finished his KU career (2000-03) with 2,097 points, 1,143 rebounds, two Big 12 titles and two Final Fours. In the NBA, he started 177 of 910 regular-season games, averaging 5.9 points and 5.2 rebounds.

"He was one of the most complete players I've ever coached," Williams said Thursday. "He could do so many things and do them extremely well and had tremendous size, too. He was one of the most competitive guys. I remember the game against Texas he had over 20 points, over 20 rebounds (24 and 23 in 90-87 victory over UT on Jan. 27, 2003 in Allen Fieldhouse). The game against Duke in the Sweet 16 in Anaheim (33 and 19 in 69-65 win on March 27, 2003) ... I loved every, every day, every game, every practice with him the entire time," continued Williams, who dismissed the idea of returning to North Carolina to coach the Tar Heels in the summer of 2000 because of a statement he made to Collison in recruiting that he would not leave KU during the Iowan's years in college.

Former KU guards Brett Ballard and Jeff Boschee, KU teammates of Collison who are now college head coaches, said they appreciate coaching players with the traits of Collison.

"He's a great person, great teammate, a guy who gives everything he's got, brings it every day," said Ballard, head coach at Washburn University, who noted, "Nick is the same guy now as he was then, just a great person."

Ballard added jokingly ... "One thing about Nick ... I've never seen a guy sweat as much as him. You'd feel sorry for the managers. I remember in Hawaii he cramped up but at the same time was sweating. I remember him trying to get off the court."

Noted Boschee, head coach at Missouri Southern State: "Nick's a hard-hat, lunch-pail type guy who comes to work every single day. He's a very honest, trustworthy individual, a selfless person. You see that with his 15 years in the NBA, going from a fairly-prominent role to somebody basically a practice player."

Boschee _ he spent some time with Collison during a recent trip to OKC in which he scouted Thunder practice for two days _ enjoyed reconnecting and reminiscing with his Jayhawk buddy.

"Off the court he was easy to be around, fun to hang around with," Boschee said. "The minivan he drove around ... it was a 1980-something minivan everybody knew about. He called it 'The Woodgrain.' We'd cruise around in it.' "

Michael Lee, current assistant coach for the NBA G-League's Santa Cruz (Calif.) Warriors, recalls having serious conversations with Collison in 'The Woodgrain.'

"I was a freshman (during Collison's junior year) and he was always there for me. You could always talk to him," Lee said. "He'd say, 'It's not that bad. You'll get through it. Keep your head up.' It was awesome to play alongside him for two years," Lee added. "He never had a bad practice, never a bad game. You knew with Nick he'd never have a bad game. Everybody liked Nick, everybody," Lee added.

Several years ago, Lee, who hails from Portland, Ore., recalls visiting Collison, who was playing for the Seattle SuperSonics, a team that moved to OKC and became the Thunder. Collison spent his entire NBA career with one franchise.

"He said, 'We're going to go downtown and hang out.' I thought we'd get in a car. We got in a boat. He was laughing when we got in this boat," Lee recalled. "We ended up playing home run derby on jet-skis. It speaks to the type of dude he is, great person, fun guy."

A guy Roy Williams will obviously never forget.