[3] During the season, he put up 17 goals and 21 assists for 38 points, causing him to be selected by the Oshawa Generals in the 2016 OHL Import Draft.

"[7] However, Tolvanen's collegiate aspirations were closed after his application was rejected by Boston College admissions due to an issue with his high school course credits on 22 June 2017.

[8] Following two seasons in the USHL, Tolvanen started his professional career in July 2017 by agreeing to an optional two-year contract with the Finnish-based Jokerit of the Kontinental Hockey League (KHL).

[13] In October, Tolvanen had recorded five goals and four assists for nine points through 12 games and was selected to represent Finland at the 2018 Winter Olympics.

[15] Tolvanen finished the regular season with 19 goals and 17 assists through 49 games to set a new KHL scoring record for players under the age of nineteen.

[16] After Jokerit were eliminated by CSKA Moscow in the quarterfinals, he signed a three-year, entry-level contract with the Nashville Predators.

[21] He was then assigned to the Predators' American Hockey League (AHL) affiliate, the Milwaukee Admirals, to start the 2018–19 season.

[24] He subsequently made his season debut that night and scored his first career NHL goal against Cam Ward of the Chicago Blackhawks.

[28] During the 2018 off-season, the Predators' coaching staff asked Tolvanen to lose weight and become quicker on the ice to help him create more room to utilize his shot.

[35] In the midst of his sixth year in the Predators organization during the 2022–23 season, Tolvanen, having appeared in 13 games and with 4 points, was placed on waivers on 11 December 2022.

[39] He finished the season with 16 goals and 11 assists in 48 games, while the Kraken qualified to the Stanley Cup playoffs, a first in franchise history.

On 18 April, Tolvanen scored Seattle's first ever playoff goal in an eventual 3–1 win in Game 1 of the Kraken's first-round series against the Colorado Avalanche.