Irresponsible defensively early in the season, the 22-year-old forward who came to the West Coast with big expectations has been benched for an entire period and even spent one game watching from the press box.
And while his offensive upside as a power forward has yet to be realized, Kassian is starting to do the little things that help earn a coach's trust.
"There's a couple mistakes I made earlier in the year that you can't make," Kassian said after Thursday's practice. "I just need to keep it simple in the defensive zone. I have done that the last couple games (and) seen results."
After being dealt for a blue-chip offensive talent, the six-foot-three, 214-pound Kassian was expected to add size and toughness to Vancouver's top-6 forwards.
But he struggled to find his game under former Canucks head coach Alain Vigneault and that trend continued once Tortorella took over this season.
"We're still in the process of trying to get Zack to process the game," said Tortorella. "Not only with the puck, but away from the puck."
Despite seeing improvement, the coach doesn't think Kassian is ready for a role on the Canucks' first two lines because it would mean big minutes against other teams' top offensive players.
Kassian was expected to get a chance on Vancouver's No. 1 line with Daniel and Henrik Sedin this season, but time alongside the superstar twins has yet to materialize.
"This is a great team we have here," said Kassian. "We have something special and I want to be part of this team any way I can. If that's third line, fourth line, first line — any possible way."
Kassian has seen more ice time the last two games after being moved up to the third unit and could be even more of a focus when the Edmonton Oilers visit Rogers Arena on Friday night.
Kassian was suspended eight games for hitting Edmonton's Sam Gagner in the head with his stick in the pre-season, forcing the Oilers forward out of the lineup for 13 contests with a broken jaw.
Gagner's teammates were fuming after the incident, but Kassian missed the clubs' first meeting of the regular season on Oct. 5 when the memories were still fresh.
"It's not going to bother me," Kassian said of any extra attention he might receive Friday. "I'm not even thinking about it at all. Our main focus as a team is getting the two points.
"We'll see what happens."
Two points is something the Canucks have been getting a lot of recently. Vancouver is riding a five-game winning streak and has three straight victories at Rogers Arena after struggling to a 1-2-3 record on its previous six-game homestand.
That recent success has come without much of a contribution from the Sedins. Henrik has one goal and one assist in his last six games, while Daniel has three assists in his last five.
"Daniel and Henrik have to lift their game up. I don't need to talk to them about that. They know that," said Tortorella. "To me, the most important adjustment is just simplifying and getting pucks to the net.
"They use each other so well (that) sometimes it's to a fault. They need to get pucks to the net."
Tortorella has stressed a puck-pressure system since joining the Canucks, but the team surrendered a ton of odd-man rushes early in the season.
Canucks goalie Roberto Luongo, who confirmed he will start against the Oilers, said he's noticed a definite change in recent weeks.
"We are playing really tight defensively," he said. "A lot of the shots are from the outside and guys are doing a really great job in front of the net. As a goalie, that's all you can ask for."
With their defensive game now on the upswing after having given up two goals or less during their current winning streak, Tortorella wants his team to take the same mentality when they have the puck.
"I think we're stiffer defensively. I think our sticks have been better. I think that's probably our most consistent area of play," he said. "I think we need to be stiffer offensively."
After the game against the Oilers, the Canucks host the Bruins on Saturday night — the first meeting between the two clubs in Vancouver since Boston's triumph in Game 7 of the 2011 Stanley Cup final.
That matchup will no doubt stir up emotions, but Tortorella stressed the importance of not looking past an improved Edmonton team that sits last in the Western Conference.
"You need to be ready to play. It's in our building. I don't think we've fully established ourselves as far as how we play in our building," he said. "I think (Friday) night's a very important game. We need to be focused or bad things happen.
"There are no easy games in our league."