Boston Celtics rookie Jaylen Brown found one way to ease his struggles with finishing at the rim early in his pro career.

Brown, the No. 3 pick in last month's NBA draft, took a no-look bounce pass from fellow rookie Demetrius Jackson and delivered a rim-rattling one-handed jam over Dallas Mavericks 7-foot-2 center Satnam Singh Bhamara during Boston's 88-82 triumph at Vegas Summer League on Tuesday.

Brown has come just as advertised: exceptionally athletic and equally raw. He's left Celtics fans swooning because of his love for contact and petrified because he's rarely been able to finish those strong drives at the basket.

Through four games, Brown has connected on just 9 of 37 shots, or 24.3 percent. A bone bruise on his right knee forced him to sit out two of the team's three games at the Utah Jazz Summer League, then likely contributed to his stuck-in-the-mud start in Vegas.

His lack of free-throw attempts in the first two Vegas outings left some wondering if his 17-attempt debut in Utah was a mirage. But Brown put together maybe his most encouraging summer performance on Tuesday against the Mavericks, getting to the charity stripe 17 times again as part of a 20-point, 10-rebound, four-steal effort.

Alas, it's that loud baseline dunk that Celtics fans will cling to. The Celtics have lacked that sort of rim-attacking athleticism in recent seasons. Every now and then guard Avery Bradley will show some sneaky hops and big man Kelly Olynyk has maintained that his "bounce is real," but Brown is absolutely fearless going at the basket and seems eager to put unsuspecting big men on a poster.

Clearly Brown's knee is feeling better after he hyperextended it while chasing a loose ball in his debut against the Philadelphia 76ers on July 4. As the Celtics launch into Vegas' playoffs, we'll get a better idea of whether Brown can consistently get to the line like he's shown in half of his appearances this summer.

Consider this: In three games at Vegas summer league, Brown has drawn a shooting foul on 25.5 percent of his plays finished, according to Synergy Sports data. This after getting to the line on 33.3 percent of his plays finished in his lone Utah appearance. For sake of comparison, Jae Crowder led Celtics regulars during the 2015-16 season by drawing fouls on 11.2 percent of plays finished.

Brown, who is shooting 69 percent (29-of-42) from the charity stripe through four summer games, knows he must improve his free-throw accuracy to maximize the whistles he's drawing. And because calls will be harder for a rookie to come by during the regular season, he must improve his shooting from all over the floor. Still, Brown has made an impression on teammates like All-Star point guard Isaiah Thomas.

"Athletic," Thomas said when asked what's stood out about Brown while watching him up close at a couple games in Vegas. "The game’s probably coming really fast for him right now. But he’s got the tools to be good. I don’t know if he’ll help us right away, but I know I’m hearing from the coaches and stuff he likes to work. He’s all ears. You need guys like that."

With Evan Turner's departure, the Celtics are thin on the wing behind Crowder. While Terry Rozier -- clearly Boston's most NBA-ready player at summer league -- is ready to vault to a more consistent rotation role, there is an opportunity for someone like Brown to carve out immediate minutes at small forward.

Celtics coach Brad Stevens acknowledges that Brown is still very raw, but likes the potential.

"He’s 19," said Stevens. "The bottom line is I’m watching a lot of the 19 year olds get more comfortable as the games go on, but none of them are knocking people’s socks off right out of the gate. Obviously he’s got a great deal of talent. He’s got a great deal to learn to be effective at this level and we’ll see. Time will tell."

For his part, Brown has repeated that "Rome wasn't built in a day." He's urged patience as he acclimates to the pro level. Celtics brass have maintained that he's a better shooter than what he's shown thus far and, even if that part of his game is slow to develop, he's distinguishing himself with a desire to attack the rim.

Brown will have no choice but to improve at the NBA level. He'll be matched up daily with the likes of Crowder, Bradley and Marcus Smart. They're going to make him work for points in practice. And they'll offer guidance on how to harness his defensive abilities (Brown's four steals in Tuesday's game were encouraging).

"I'm just trying to establish myself, play the game the right way with my teammates, have fun, make the right plays and get adjusted to the pro game," said Brown. "It's different from college. It's a little bit faster, so I'm just trying to get as comfortable as I can on the court."