By Matt Kalman, CBS Boston

BOSTON (CBS) — Full training camp hasn’t even started yet and Bruins defenseman prospect Jakub Zboril has already made an impression.

When asked Tuesday before departing with the Bruins for China which players stood out during last weekend’s rookie tournament, coach Bruce Cassidy mentioned Zboril first.

“I liked Zboril’s game,” said Cassidy, a connoisseur of defenseman having been one himself. “I thought he was more consistent, more assertive. Much improved from the year before.”

Zboril, who was among the defense corps that joined Boston on its China-bound charter Tuesday, had to be pleased that his potential coach brought up his name before going down a list of a handful of other players that impressed in Buffalo. The 21-year-old also had to be pleased that Cassidy took notice of the player’s assertiveness because that’s an area Zboril really wanted to work on heading into this year.

People in the Bruins organization have echoed the sentiments of scouts from outside the organization that Zboril can sometimes be aloof. In Buffalo, he was up in the play pushing the offense but sometimes got lost on defense in the Bruins’ first game. The next night he calmed down and played well again.

“I already talked to some coaches, they like my game, that I didn’t quit on any play,” Zboril said. “That was my biggest area that I had to improve.”

Zboril’s first season of pro hockey last season proved to him how difficult it is to play against bigger, stronger and older men in front of the net after dominating that section of ice in junior. The key has been the tricks the 6-foot, 200-pound blueliner has learned about battling in front.

“Let’s say I’m going to go to the left side just to bait a guy. So I’m just going to put my stick on the left side so he knows I have that pressure on his left side, but all of a sudden when he goes to turn I’m going to close him quickly, so you can actually help out yourself,” Zboril said.

After coaching Zboril all of last season and then at the rookie tournament, Providence coach Jay Leach has seen improvement.

“I think the biggest thing for him is he just needs to feel comfortable and confident. He’s got a lot to his game that will translate,” Leach said. “He can skate, he’s hard when he wants to be, he can shoot, he’s got a heavy shot. And he’s smart. I think it was really good for him to grow, to season a year in Providence because he just matured a year.”

Once it was normal for a defenseman, even one drafted 13th overall (in 2015), to spend at least a couple years in the AHL developing. Circumstances around the league have changed and many players Zboril’s age and younger have made the leap to the NHL quicker.

Zboril is balancing his desire to already be in the NHL with the patience it takes to stick to the development program the Bruins have created.

“Until you get a chance you just have to hold on, do your best, want to improve, want to learn,” he said. “And there’s so many guys you can learn from and you just have to take advantage from being in an organization of really good people and be asking questions.”

Even when the Bruins had eight veteran NHL defensemen, Zboril refused to say it was impossible to make the lineup. The trade of Adam McQuaid reduced that number by one but there are plenty of other defensemen, young and older, competing with Zboril for a spot on the depth chart. More than one injury to the defense corps could open up an opportunity.

Zboril has to hope he can continue to build off the impression he made in Buffalo.

Matt Kalman covers the Bruins for CBSBoston.com and also contributes to NHL.com and several other media outlets. Follow him on Twitter @MattKalman.