The Celtics' rookies are making a strong first impression

LAS VEGAS – As the Celtics wrapped up practice on one of the auxiliary courts at UNLV on Saturday, rookies Chris Cenac Jr. and Dillon Mitchell made their way over to a side basket and started putting on their own dunk contest.

Cenac went first. The 6-foot-11 center took off, went between the legs with his left hand and hammered home a violent one-handed dunk with his right.

Mitchell answered with a one-handed 360.

The impromptu dunk contest reinforced what has become crystal clear through Boston’s first two Summer League games: the Celtics drafted two elite athletes who love playing above the rim.

Ask anyone around Boston’s Summer League team this week about Cenac or Mitchell and the same word keeps coming up.

Athletic.

“They’re both super athletic,” Jordan Walsh, who has been around the Celtics Summer League team at games and practice this week, said. “That’s something that Boston loves, obviously. Two super tall guys that are super athletic and want to play hard.”

Added teammate John Tonje, “They’re both super talented. Obviously, very athletic and super dynamic players.”

The athleticism has turned heads, and for good reason.

In the early going of Summer League action, both rookies have made an impact with stingy defense, relentless effort on the glass, nonstop energy and constant pressure at the rim, all areas Brad Stevens highlighted as priorities after the Celtics’ season came to an end.

Through two games, Cenac has totaled 16 points, 15 rebounds, including six offensive boards, five blocks, one steal and one assist while posting a +17 plus-minus. Four of his six made field goals have come in the paint, including three in the restricted area.

Although his second game was much quieter than his 14-point, 10-rebound, four-block Summer League debut, the 19-year-old still flashed why the Celtics were so intrigued by his upside.

Early in the second quarter against Charlotte, Cenac blocked Hornets center Ryan Kalkbrenner at the rim, secured the loose ball himself and, after receiving an entry pass on the other end, fired a perfect pass to Hugo Gonzalez in the corner for three. It was one sequence that showcased his length, mobility and feel for the game.

Mitchell has had a similar impact.

The 22-year-old has totaled 30 points, 11 rebounds, including nine offensive boards, eight steals, four blocks and two assists through two games. Ten of his 12 made field goals have come in the restricted area, a reflection of how relentlessly he has attacked the basket.

The former St. John’s standout erupted for 24 points on 10-of-20 shooting, along with eight rebounds, six steals, two blocks and two assists in Sunday’s 87-75 win over the Hornets.

Perhaps just as encouraging, Mitchell knocked down two of his five three-point attempts against Charlotte. That’s one more than he made during his entire final season at St. John’s. He shot just 1-for-15 from beyond the arc last year and 11-for-57 (19.3%) across his collegiate career.

“He was so alive today. He played with such great energy. He crashed every time. He had, like, three different times where he almost had a tip dunk. When he’s playing with that kind of pop, he’s going to be really good. And then any time he gets an open three, he should shoot it. He did that today, and he was confident.”

Summer League results can be misleading. The numbers rarely tell the full story. The traits, however, often do.

Cenac and Mitchell have played with confidence, defended, rebounded, pressured the rim and consistently found ways to impact the game. They still have a long way to go in their development, but they’ve already shown they possess the size, athleticism and feel that give them a legitimate chance to carve out NBA roles.

Through two games in Las Vegas, it’s easy to see why the Celtics bet on their upside.