He said he had gotten tired last season at different times, but he trained over the summer in order to fix that, in order to allow himself to make the best use of the minutes he would be given. And he has been given a lot of them.
"Maybe I couldn't handle the minutes right away [last season], but this year I feel in better shape and I'm one more year experienced, so I think this year I'm ready for that," he said. "I could play 30 minutes every night and it would be awesome."
He had been happy with his performance last season, but believed he could be better, wanted to be better, and thought he could improve on a season when he played all 82 games, with 41 points (nine goals, 32 assists).
In 30 games this season, Ristolainen has 21 points (two goals, 19 assists), putting him on pace for a career-high 57 points in his fourth season in the NHL.
"I've got to keep getting better," he said. "I am still a lot of potential and can be a lot better player than I am now. I've got to every year be better and work hard on the ice. I'm a two-way [defenseman], I've got to do all the things out there, so I've got to be better defensively and for sure I need to score more. Only [two goals] this year. A lot of opportunity and shots, so that's the one thing: I've got to find a way how to score."
He has fixed one impediment to scoring by going back to the sticks he used last season. He switched them over the summer, wanting to try something new, and they had seemed to work. He had no problems while training, no problems during the World Cup of Hockey 2016 playing for Team Finland. But when he arrived in Buffalo, the sticks would not stop breaking, sometimes two or three a game.
It had gotten in his head, making him worry every time he shot the puck that they might break. As he said, "Then you start worrying about, should I pass more?"
That is no longer his concern, though he still mourns a few of the lost chances he had.
For now, his focus is on the future, on the Sabres continued improvement, on his own continued improvement. It has not been an easy season for the Sabres, who thought they were bound for the Stanley Cup Playoffs before being sidetracked by a series of injuries.
But Ristolainen said he thinks there is hope ahead.
"For sure I want to be the top [defenseman] on the Sabres for a long time and then League-wise I want to be one of the best [defensemen] out there one day," Ristolainen said. "The other thing I want to be: I want to be a winner. I want to be the guy who you can win with. I want to win the Stanley Cup here in Buffalo. That's my dream and my goal."