Kelly Olynyk

Boston Celtics forward Kelly Olynyk rebounds the ball as he waits for a shoot during Celtics basketball team media day in Waltham, Mass., Monday, Sept. 29, 2014.

(AP Photo/Elise Amendola)

WALTHAM – After emerging over the second half of his rookie season, Boston Celtics big man Kelly Olynyk spent most of his summer on a basketball court. He played in summer league, competed for the Canadian national team, hosted a camp for children, and even found time for trick shots in the dining room.

The 23-year-old returned to Waltham – where he actually stayed for a lot of the offseason – with a leaner, stronger body. The coaching staff hopes he continues the momentum into his second season.

“I think our best bet is to make him a big part of what we’re doing,” head coach Brad Stevens said Wednesday before the second of two practices. “And the reason (for) that is because he’s a skilled, savvy basketball player that can play a number of positions and stretch the floor for you.”

By the end of last season, Olynyk qualified as one of Boston’s best players. Over the final three games of his rookie season, he posted All-Star numbers: 25.3 points and 9.7 rebounds. The statistics were inflated by a lack of competition, to be sure, and by that stage of the season, games felt kind of like a Saturday morning open gym. But the hot stretch only highlighted the many improvements he revealed after the All-Star break.

“First of all, I was feeling good,” he said. “I had a bunch of nagging stuff during the middle of the season that kind of held me back a little bit. So when your body’s feeling good, your confidence is high, and you're getting on the floor and you're getting that opportunity, you have the opportunity to do some stuff, and I just tried to capitalize."

Over the second half of the season, he scored efficiently from all over the court, boosted his defensive rebounding, continued to demonstrate rare passing skills for a big man, and did it all while taking on a bigger role in the offense. His defense was still hindered by athletic limitations, but he barely resembled the unsure youngster who struggled for the first few months of the season.

"It's good when your progress trends upward and not downward," Olynyk said.

"That was kind of my goal throughout (last) year, just keep getting better every day. That's the goal for anybody. Better yourself today – better than you were yesterday – and keep going on an upward trend."

With Brandon Bass, Jared Sullinger and Tyler Zeller, the Celtics have a crowded frontcourt with several players – including a trio of young ones – who all deserve minutes. Olynyk might not start, but he proved himself last year as a rising talent, and the Celtics think he should only grow more comfortable in Year 2.

“I thought he made great progress last year,” Stevens said. “I think he’s made a lot this summer.”