R.J. Hunter’s professional career got off to a bit of a rough start.

The first-round draft pick of the Boston Celtics out of Georgia State missed his first eight shots over two games playing in the Utah Jazz Summer League earlier this month. In the finale of the three-game of the tournament, he got going in a big way.

“Huge,” Hunter said of a 3-pointer he made on his way to an 18-point game. “It was huge. I thought I was in my own head early. Once I figured out it’s just basketball and you play your game. I thought that helped me out and slowed everything down.”

Hunter, the No. 28 overall selection, moved on with the Celtics to the Las Vegas Summer League. There the shooting guard has helped the Celtics to a 3-0 record and a No. 2 seed after three preliminary-round games concluded Tuesday. The Celtics will play the winner of Wednesday’s Timberwolves-Trail Blazers game Friday to start the seeded portion of the tournament.

In six games between both summer leagues, Hunter has averaged 10.8 points, 2.3 rebounds and 0.8 assists. Since those first two games, Hunter has averaged 16.3 points.

“That is the part I’m still struggling with,” Hunter said of finding where his shots will come from in the Celtics’ offense. “In college, my spots were everywhere. Now, it’s just the sides of the court. I’ve still got to figure that out.”

Hunter’s shots did come from everywhere playing at Georgia State. He left the school, and playing for his father, Ron, with a season of eligibility remaining. He is the school’s all-time leader, with 1,819 points. He helped the Panthers become the one of the lasting memories of this year’s NCAA Tournament with a 30-footer with less than three seconds remaining in an upset of No. 3 Baylor. He was chosen Associated Press All-American honorable mention as a junior, with a career-high average of 19.7 points.

Hunter is in the NBA now and there is a big difference from college. A big difference.

“You can’t get exposed,” Hunter said of his biggest adjustment to the pro game. “In college, I always say, you can take some plays off. It’s bad to say that but you do. Here if you take plays off you end up on (ESPN’s) SportsCenter.’ You have to stay engaged in every possession.”

There is no question Hunter can shoot. His transition to the NBA will be in significantly predicated on his defense. Hunter said playing man-to-man will get a player exposed and something of which he is well aware. The Celtics play a help-defense scheme and that has helped in the adjustment. Even in summer league, it helps to have a front-court player behind as another line of defense. Hunter said he is still learning and needs to fight through screens better.

“Defensively he’s picked up our stuff pretty well in just 10 days,” Celtics coach Brad Stevens said on an NBA TV broadcast. “He’s got a ways to go and he’ll get stronger, and he’s got a lot of work ahead of him, but I like what he can do.”

Yes, there is a long way to go for Hunter. But he has already come a long way.

He was Georgia State’s first first-round pick in school history and the first player selected in 32 years.

“Right now, on a scale of 1 to 10, like a 6 or 7,” Hunter said of his confidence level after he scored 21 points in a Las Vegas Summer League win over the 76ers on Sunday. “(In Utah), I was like a point-6. I told somebody, I walked out and saw the crowd and thought I was in a middle school game. That’s part of the transition.”