Thomson is a pending Group 6 UFA this summer, and his late-season NHL callup has certainly improved his NHL stock.
Lassi Thomson bet on himself last summer, but it is fair to assume that he would not have bet on being in the position he was in on Monday night: playing in game two of the Eastern Conference quarterfinals.
When the Ottawa Senators announced on June 15, 2025, that they had signed Lassi Thomson to a one-year, two-way contract, it was fair to wonder why.
It was not a matter of asking, “Why would an organization want to add a then-24-year-old right-shot defenceman?” Not when every organization in the league is looking to add inexpensive and relatively young right-shot defensive depth.
It was simply a matter of asking, “Why would Lassi Thomson want to return to the Senators’ organization?”
Drafted out of the Kelowna Rockets of the WHL, Thomson was the 19th overall selection of the 2019 NHL Draft by the Senators. The Finnish import product was coming off a strong offensive campaign in which he tallied 17 goals and 41 points in 63 games.
Thomson would return to Finland the following season to play for Ilves in the Liiga, and once his loan to Ilves ended, he arrived for training camp with Ottawa in 2020.
The defenceman would play parts of the next four seasons in the Senators’ organization, even getting into 18 games for the Senators as an AHL recall. In September of 2023, however, it appeared that Thomson’s time with the organization was over. Unable to crack the Senators’ blue line after training camp and the preseason, the Finnish defenceman needed to clear waivers to be returned to the team’s AHL affiliate in Belleville.
The Anaheim Ducks claimed Thomson off waivers on October 8, 2023, but he would never appear in a game for them. When they subsequently tried to put him through waivers to send him to their AHL affiliate the following day, the Senators re-claimed Thomson and sent him to Belleville.
On a relatively weak Belleville team, Thomson had the worst offensive year since playing professionally in North America, compiling just six goals and 21 points in 67 games.
That performance and the offseason awareness that the Senators had Artem Zub, the recently acquired Nick Jensen, Travis Hamonic, and depth pieces like Nikolas Matinpalo and Jacob Bernard-Docker in their midst, there simply was very little opportunity for Thomson to crack Ottawa’s lineup.
Thomson looked overseas for an opportunity to reestablish himself, eventually signing with the Malmö Redhawks of the SHL.
It turned out to be a smart play, as no defenceman in the Swedish league scored more than Thomson’s 17 goals. He finished the season eighth in scoring by a defenceman, recording 29 points in 50 games.
At the conclusion of his season, the Senators came calling.
“We had a lot of talks over the summer with (management) and the coaches,” Thomson explained. “We saw an opportunity to get a couple of games in, and it was a good opportunity. Obviously, with (the Senators) making the playoffs, the (roster) was kind of settled. But I wanted to come here, have a good year, have that confidence in myself, and maybe get the chance (to play).”
Making the decision to leave Sweden, where he was enjoying success, was not easy.
“Of course it was tough,” Thomson stated while describing the decision he had to make. “Obviously, I liked playing in Europe. It was close to home, but like everything else, it was still a bit different.
“I was obviously playing good, but obviously, I've been (in Ottawa), and I know the hockey here. Everybody wants to play in the NHL. I'm still 25 years old, and kind of young. So I think I'm not losing anything by just coming over here to try, and I wanted another chance for this.”
After training camp, however, Thomson was returned to his familiar Belleville, where he simply waited for his chance.
As injuries began to mount and other defencemen were recalled, Thomson continued to focus on his game, hoping that one day the call would be his.
“Obviously, it is kind of frustrating seeing your teammates from Belleville are getting called up, and you're not getting that chance,” admitted Thomson. “But obviously, you have to try to think about it the other way and try to be positive than worry if (a recall) is going to be coming or if it's not coming.
“So, I tried not to get too frustrated. I will say, I just tried to enjoy the hockey. That was the biggest thing for me this year. Just come here and enjoy the hockey. Whatever is going to happen, it's gonna happen. Maybe everybody stays healthy, and you're not going to get a chance. So, I just try to be happy and positive around the other guys. I think it's been working.”
So, Thomson kept his head up and played hard, turning in what was arguably his best and most complete season on this side of the pond. In 55 games with Belleville, Thomson had 14 goals and 25 points while registering a positive plus-minus rating (+1) on a team that gave up the second-highest number of goals (262) in the AHL.
Eventually, it was Thomson’s turn to get a recall and play his first game.
Unfortunately, seven shifts into his first game since November 22, 2022, Thomson sustained a lower-body injury when a New York Ranger fell on his leg. Four minutes and 25 seconds into his NHL return, the defenceman’s night was done.
“I was pretty down after that,” described Thomson. “Mentally, just finally getting that chance and then getting hurt right away. It wasn't fun.”
No one could have blamed Thomson for thinking that the game at Madison Square Garden could have been his last. With other defencemen being close to returning from their own respective injuries and the uncertainty of when he would be available to play again, the possibility that he would not have another chance this season felt very real.
Having the presence of a fellow Finnish defenceman and friend in Nik Matinpalo, certainly helped Thomson.
“It helps a lot (having Matinpalo here),” Thomson laughed while looking at his friend and stallmate. “Obviously, it's always fun to have another Finnish guy. It just helps a lot of things. When you're off the ice, you have somebody else. You’re living at the hotel, so it's great to have somebody who's living there and just kind of help take care of you a little bit more. So, he’s been unbelievable.”
With the help of the team’s trainers, Thomson described the next few days as “weird”, but he recovered quickly enough and dressed in the lineup five days later.
Thomson would go on to play in 11 games for the Senators down the stretch, contributing three assists. In the 141 five-on-five minutes that Thomson played, the team would generate 52.31 percent of the shots (CF%), 55.65 percent of the shots on goal (SF%), 66.67 percent of the total goals (GF%), and 60.19 percent of the expected goals (xGF%).
To Thomson’s credit, he played well in the limited and sheltered third-pairing minutes that were afforded to him. And more importantly, he demonstrated to the coaching staff that he could be an option for them in the postseason, if needed.
The Senators continued to be beset by injuries on the blue line heading into their first-round matchup with the Carolina Hurricanes, and there was some discussion over which defenceman should play on the Senators’ third pairing to open the postseason.
Thanks to his handedness and physicality, the veteran Dennis Gilbert was called upon. But when Artem Zub sustained a lower-body injury while hitting Hurricanes forward Seth Jarvis in game one and left the game, it opened the door for Thomson to enter the lineup.
No player wants to see one of their teammates get hurt to create an opportunity, but playing in an NHL playoff game is something that Thomson has dreamed about.
“(Playing in a game), it's pretty awesome,” Thomson said. “This is the point where you want to be, and that's why I came over here, to play in these games. It's pretty unreal.”
Thomson’s career took a few detours, but now he is playing in meaningful hockey games where scouts and other front offices from other franchises are watching.
As a 25-year-old on an expiring contract who has played in fewer than 80 career NHL games, Thomson is slated to become an unrestricted Group VI free agent this summer. Thomson has grown and matured a lot over the past two seasons.
Though he'll serve as a black ace on Thursday night, the way that Lassi Thomson has stepped into the Senators’ lineup and contributed, he looks poised to sign another NHL contract this summer.
Graeme Nichols
The Hockey News
This article was first published at The Hockey News Ottawa. Check out more great Sens features from The Hockey News at the links below: