[2] He was named to the WHL's Western Conference Second All-Star Team alongside teammates Parker Wotherspoon and Morgan Geekie.

[12] Välimäki suffered a high ankle sprain on 23 November in a game against the Vegas Golden Knights which limited his season.

[20] Välimäki made a successful return from injury with Ilves, playing in a key role and producing at a point-per-game pace through 19 regular season contests, recording two goals and 17 assists.

[2][23] Prior to the 2022–23 season, after being unable to make the Flames opening night roster, Välimäki was placed on waivers before he was claimed the following day, on 9 October 2022, by the Arizona Coyotes.

[25] He recorded his first point with the Coyotes on two games later on 22 October, assisting on Dylan Guenther's first career NHL goal in the second period of a 6–2 loss to the Ottawa Senators.

[26] He scored his first goal in a Coyotes uniform on 3 November in the third period to break Scott Wedgewood's shutout bid in a 7–2 loss to the Dallas Stars.

[29] Establishing a regular role within the Coyotes on the blueline, Välimäki was signed to a one-year, $1 million contract extension at the mid-point of the season on 24 January 2023.

[2] In his second season with Arizona in 2023–24, Välimäki suffered an injury early on when on he was struck in the face with a puck in a game on 15 November against the Dallas Stars.

[31] He underwent surgery to fix the damage, but the process in which he was left for several hours without care at a Dallas hospital was investigated by both the NHL and the National Hockey League Players' Association.

[35] Välimäki was named to team Finland at the 2015 IIHF World U18 Championships, which eventually earned a silver medal after a 2–1 overtime loss against the United States.

The following year Välimäki was named captain and led Finland to the gold medal at 2016 IIHF World U18 Championships defeating Sweden 6–1.

In December 2017, Välimäki was named captain of Team Finland at the 2018 World Junior Ice Hockey Championships.

[37] Finland was subsequently eliminated in the quarterfinals against the Czech Republic with a final score of 4–3,[38] and Välimäki finished the 2018 World Juniors with one goal and three assists in six games.