In 2013, just a year before he was tasked with guiding the Cavaliers during LeBron James’s celebrated return to Cleveland, David Blatt was coaching the Euroleague powerhouse Maccabi Tel Aviv. That summer, he invited 16-year-old Croatian prospect Ante Zizic to train with the team. Blatt was immediately struck by Zizic’s fearlessness as he battled against men twice his age.
Related: Q&A with David Blatt on Ante Zizic’s development and potential.
“From that point in time, I always followed him and followed his progress,” Blatt said in a telephone interview, “because he very much impressed me as a kid that was beyond his years, both mentally and physically.”
Last June, the Celtics selected Zizic with the No. 23 pick of the NBA draft, but they had such a crowded roster that they asked him to stay overseas, where he was playing in the low-level Adriatic League.
After Blatt was fired by the Cavaliers midway through last season, he resurfaced in the Euroleague as coach of the Turkish club Darussafaka Dogus. And as he constructed his roster, he kept thinking about Zizic. In December, he acquired him.
Just like that, the learning curve of one of the Celtics’ elite prospects would be accelerated. Zizic, 20, found himself in the second-best pro basketball league in the world, being instructed by a coach who was just a year removed from guiding LeBron.
“I think this year I have improved my game, I improved my body and gained experience,” Zizic said in a telephone interview. “So I think right now, I am ready for the NBA.”
In 11 games, the 6-foot-10-inch center is averaging 9.7 points and 7.1 rebounds over 23 minutes. Back in Boston, his ascension has made him one of the shiniest assets in a treasure chest that is overflowing with them, as Celtics fans dream about what he might become. The Celtics would like to temper expectations, but their excitement is clear.
“He just turned 20 in January, and he punishes grown men physically,” said Celtics director of player personnel Austin Ainge. “He hits hard and he’s a physical presence out there. As much as I loved Ante and believed in him, I was surprised how much success he had this early in Euroleague.”
Zizic’s strong play at such a high level has only strengthened the Celtics’ confidence in the next step.
“July 1 just has to roll over on the calendar, and we’ll sign him,” Ainge said. “He wants to be here, and we want him here.”
Zizic hoped it would be that simple last year. After he was drafted, he was frustrated to learn that there was no room for him on the roster. He came to Boston and put on a Celtics cap and posed for pictures at an introductory press conference, and then he was on a plane back to Europe.
“Of course the NBA is a dream of any child who starts to play basketball, but when you sit after the draft, you start thinking about your career,” Zizic said. “And if somebody says you’ve got one more year to play overseas and you can improve your game to bigger level, then it’s not too hard to stay back. All the time you know you’re close to the NBA, and you work for it.”
Zizic said he is working to improve his midrange jump shot, and he believes his developing ability to play both power forward and center will make him an asset in Boston, where coach Brad Stevens places great value in positional versatility.
Celtics home games generally tip off at 2:40 a.m. in Istanbul, so it has been a challenge for Zizic to see his future team. But he watches archived games and tracks highlights and box scores. Each game makes him more eager to be a Celtic.
“They have some unbelievable games and play very good, and I enjoy watching them because they are a young team that plays very good Celtic basketball,” Zizic said. “They play big defense, and you can see great team chemistry.”
Zizic has noticed that the Celtics’ greatest weakness is rebounding. That is difficult for him to see, because he knows that is one of his greatest strengths. He knows he could be giving his future teammates a boost right now.
“I go on every rebound, so I think I can help on that, for sure I can,” Zizic said. “I can grab some bonus rebounds. I have a great work ethic and always will give my maximum.”
But he is being patient, and he is excited about Boston’s potential, both next year and beyond.
He knows that players like Isaiah Thomas and Al Horford make the immediate future bright, and he also peers deeper into the future, at a young core that could include Marcus Smart, Jaylen Brown, and the high picks the Celtics will likely receive from the Nets in the next two drafts.
“I think the Celtics have a great opportunity next season to have big results,” Zizic said. “But the next few years they will still have a young team, and I think that in two or three seasons when the team takes our experience if we will play together, I think they are ready for some even bigger results.”
Austin Ainge and Zizic exchange text messages several times a week, but the correspondence usually has little to do with basketball instruction. The Celtics are careful not to meddle with Zizic’s training regimen while he is playing in Turkey.
Zizic said it has been immensely helpful playing under Blatt, and that when the season ends, he will ask him more about the NBA.
Blatt said he did not acquire Zizic to mold him for the Celtics, but that the sides have communicated and are aware of the ways they can help each other. For the Celtics, it is an added benefit to have Zizic playing for an English-speaking coach who uses terminology that is common in the NBA.
Blatt said Zizic reminds him of Oklahoma City Thunder big man Steven Adams, adding that his work ethic would allow him to accomplish more than many imagined.
“Without question, Ante brings to the table a level of energy and intangibles that will allow him initially as a role player to contribute,” Blatt said, “because he’s going to rebound, he’s going to run, he’s going to go after loose balls, he’s going to be able to finish and he’s going to compete.”
Blatt said the floor spacing in the NBA should help Zizic as he improves his skill set, but that the level of athleticism could initially be jarring, because as powerful as the Euroleague is, it is not the NBA.
Still, he is confident that Zizic’s competitive fire will make the adjustment easier.
“You are not going to find a better kid than Ante Zizic,” Blatt said. “And I know how easy it is for people to say things like that, because that’s what people do when they want to support their player.
“But I’m telling you, all b.s. aside, you will not find a better kid than Ante Zizic. You will not. Anywhere.”
Adam Himmelsbach can be reached at adam.himmelsbach @globe.com. Follow him on Twitter @adamhimmelsbach.