Oklahoma star Trae Young is leaving for the NBA after a standout freshman season that ended with him leading the nation in scoring and assists.

The 6-foot-2 guard averaged 27.4 points and 8.7 assists this season, and many projections have him going early in the first round of the June 21 draft. He announced the move on Twitter and posted the reasons for his decision on ESPN early Tuesday, saying he was ready to put in the work needed to play in the NBA.

"I know there will be doubts again as I prepare for the draft. I don't pretend to be ready to play in the NBA today, but I am determined to do what I've always done: invest in the work to prepare for the league and the incredible challenges it presents," he wrote.

Young grabbed headlines early in the season when he scored 43 points against Oregon on Nov. 26 and less than a month later tied the NCAA record with 22 assists against Northwestern State. He later scored at least 40 points three times in a six-game span. Along the way, a who's who of NBA stars, including LeBron James, Stephen Curry and Chris Paul, became fans.

Young had a flair for the dramatic, too. He scored 22 of his 27 points in the second half in a 75-65 win over Texas Tech on Jan. 9. He had 24 points in the second half against TCU and five more in overtime in a 43-point outburst that helped Oklahoma beat TCU 102-97 on Jan. 13. He had 18 of his 26 after the break in an 85-80 win over Kansas. He scored 31 of his 44 points in the second half to help the Sooners top Baylor 98-96.

Young made his first major adjustment after a loss to Oklahoma State, when he scored 48 points on 14-for-39 shooting in a loss. He listened to Oklahoma coach Lon Kruger, who wanted him to stay aggressive but be smarter. The next game, he took only nine shots in that win over Kansas.

"We're extremely pleased for Trae," Kruger said. "We're very excited for him going forward and the next chapter in his basketball career. We expect it to all work out for him in a fantastic way."

Young is the first major-conference player in NCAA Division I to total 800 points and 250 assists in the same season, finishing with 876 points and 279 assists. His points are the fourth-most in a single season by a Sooner, trailing only Wayman Tisdale (932 and 919) and Buddy Hield (925).

Oklahoma reached as high as No. 4 in the Top 25, and Young was an early favorite for most player of the year awards. That changed when the Sooners lost seven of their final nine regular-season games and were bounced by Oklahoma State in the opening round of the Big 12 Tournament.

Still, Young ended the regular season as the national leader in both scoring and assists. He closed the season with 28 points and seven assists in Oklahoma's 83-78 overtime loss to Rhode Island in the first round of the NCAA Tournament. He did it all while dealing with the pressure of playing for his hometown team.

"The basketball world was studying every move I made, and I am proud of how all of us — my coaches, my teammates and myself — handled it," he wrote on ESPN. "In the end, I have to make the decision that I believe is best for me, but it doesn't mean I do so without a heavy heart, without some regret that we won't get to run it back together next season."