"I'm closing one of the most amazing chapters of my life," Cockburn told ESPN on Wednesday. "I'm proud of what we accomplished in college, but I am not sure it can get much better than that. It's a scary challenge now and I'm excited to rise to the occasion and try and prove people wrong.
"Thinking back to where I was three years ago when I entered college -- people would be amazed to see the progress I made in becoming a two-time All-American. I'm planning on doing the same exact thing in my professional career: pushing my game to new heights."
Cockburn already entered the NBA draft twice in 2020 and 2021 and cannot withdraw his name from consideration for a third time, according to league rules, making him ineligible to return to college basketball.
"I'm 100% in now," Cockburn said. "I'm not going back to college. I'm signing with agent Todd Ramasar. I've tested the waters enough, I'm 100% dedicated to going all the way."
Cockburn, a consensus first-team All-American, was the only player in college basketball to average over 20 points and 10 rebounds per game this past season. He led Illinois to a 23-10 record and a Big Ten championship, which the Fighting Illini shared with Wisconsin. It was the first time Illinois won a regular-season title since 2005.
"If you watched us play, we had a lot of ups and downs," Cockburn said. "A lot of injuries, COVID, players coming in and out -- it was tough. We had to adjust. People are going to be wondering years from now what it was like to play college basketball during a pandemic.
"It was hard to be an All-American two years in a row. We proved to be winners regardless. We had the most wins in the last three years in the Big Ten of any team. People will remember that forever. NBA teams know I'm a winner now. I love to have fun, but I'm a competitor. It wasn't about my individual goals. Winning was always the priority. That speaks for itself."
A 7-foot-1 big man born in Kingston, Jamaica, Cockburn was named first-team All-Big Ten for the second straight season. He was a finalist for several player of the year awards, including the Wooden and Naismith as well as the Kareem Abdul-Jabbar Award, presented to the nation's best center.
"My dream is to be one of the best players in the NBA, especially from Jamaica," Cockburn said. "I'm playing for something bigger than myself. This is for my country, my people."
Cockburn, the No. 89 prospect in the ESPN 100, established himself as one of the most physically imposing players in the college game the past three years, with his 7-foot-4 wingspan, 9-foot-3 standing reach and 285-pound frame. His 341 points scored with his back to the basket ranked second in college basketball, according to Synergy Sports Technology.
"I know I'll have to be a different play in the NBA than I was in college," he said. "I'm excited about the opportunity. It won't be about being a low-post scorer against double teams. I'm actually excited about not seeing double teams anymore. From now on it's about my dedication to being the most fit athlete possible. I look around the league and I'm inspired by the level of physicality and conditioning. That's where I need to get. There's no fat on my body, but I can lean out and get faster, quicker, more athletic.
"The NBA values players like Steven Adams and Jonas Valanciunas -- guys who set great screens, who know the pick and roll game, how to slip and seal, how to be a physical defender and rebounder who blocks shots. My size can be a major advantage in the NBA. I don't need the ball to be happy."
With Cockburn off to the pro ranks, Illinois will need to replace possibly five of its top seven scorers, with Alfonso Plummer, Trent Frazier and Da'Monte Williams all out of eligibility after five years in college. Sophomore Andre Curbelo elected to transfer to St. John's, while senior Jacob Grandison is currently undecided about returning for his fifth season of eligibility.
Illinois is bringing in a strong recruiting class with three top-100 prospects in Skyy Clark, Ty Rodgers and Jayden Epps, and is expected to be aggressive pursuing veterans in the transfer portal, especially in the frontcourt. Sophomore power forward Coleman Hawkins looks poised for a breakout season, and freshman small forward RJ Melendez was highly regarded coming into college.
The NBA draft combine will be May 16-22 in Chicago, and the draft will be June 23 in Brooklyn, New York.
Jonathan Givony is an NBA draft expert and the founder and co-owner of DraftExpress.com, a private scouting and analytics service utilized by NBA, NCAA and International teams.