After playing in the
Finnish junior leagues, Koivu began playing for
TPS of the
SM-liiga as a 17-year-old in the 2000–01 season, the same team for which older brother
Saku also once played. He was selected sixth overall in the
2001 NHL entry draft by the
Minnesota Wild and continued to play with TPS for three more seasons.
Minnesota Wild (2005–20) Koivu moved to
North America for the
2004–05 season to play for Minnesota's
American Hockey League (AHL) affiliate, the
Houston Aeros, while
that NHL season was canceled. He made his NHL debut with the Wild in early November 2005 after suffering an injury in the
2005–06 preseason. After scoring 21 points in his rookie season, Koivu signed a one-year contract with the Wild on 18 July 2006. In
2006–07, Koivu improved to a career-high 20 goals, 34 assists and 54 points. Injuries slowed him down in his third season, however; in a game against the
Vancouver Canucks,
defenceman Mattias Öhlund retaliated to an unpenalized elbow from Koivu and slashed him, breaking a bone in Koivu's leg. Öhlund was given a four-game suspension and Koivu missed 24 games as a result of the injury. On 30 June 2007, the Wild re-signed Koivu to a four-year, $13 million contract worth $3.25 million annually. in October 2010 Before the
2008–09 season commenced, Koivu was announced as a permanent
alternate captain for the entire season, along with teammate
Andrew Brunette, assuming they were not captain for the month (the Wild captaincy was rotated among the players on a monthly basis, each season). But Koivu started the 2008–09 season as team captain for the months of October and November. Though rumors swirled that then-Wild Head Coach
Jacques Lemaire was close to ending the captain rotation and naming Koivu the permanent captain, he was replaced by
Kim Johnsson in December, reverting to his role as
alternate captain. In January 2009, Koivu was once again honoured with the Wild captaincy after only a month's hiatus. On 16 October 2008, Koivu tied a Wild franchise record for most assists in a game with four against the
Florida Panthers. He also added a goal for a career-high five-point game as the Wild defeated Florida 6–2. In July 2009, it was announced that Koivu would be on the cover of Finland's version of
EA Sports'
video game NHL 10. He was also voted the best Finn in the League by NHL.com. Koivu was named the first permanent captain in Wild franchise history on 20 October 2009. During the ensuing off-season, he signed a then-franchise-record seven-year, $47 million contract extension on 16 July 2010, which went into effect during the
2011–12 season. On 12 January 2012, Koivu was selected to his first
NHL All-Star Game. However, he was unable to participate due to injury and was replaced by Oilers forward
Jordan Eberle. On 18 March 2014, Koivu recorded three points in a 6–0 win over the
New York Islanders, in the process becoming the Wild's all-time leading scorer with 438 points in 588 games. On 28 February 2016, Koivu surpassed
Nick Schultz's 743 games played with the Minnesota Wild to own this franchise record as well. Koivu was named a finalist for the
Frank J. Selke Trophy as the best defensive forward for the
2016–17 season, which was ultimately given to
Boston Bruins centre
Patrice Bergeron and Koivu finishing third in the voting behind Bergeron and
Anaheim Ducks centre
Ryan Kesler. On 18 September 2017, the Wild signed Koivu to a two-year, $11 million contract extension worth $5.5 million annually. On 6 February 2019, Koivu was ruled out for the remainder of the
2018–19 season after suffering a tear in his
Anterior cruciate ligament (ACL) and meniscus in his right knee. The incident occurred the night before in a game against the
Buffalo Sabres. He ended his season with eight goals and 29 points in 48 games. The Wild retired Koivu's number 9 on March 13, 2022, becoming the first player in franchise history to receive that honor.
Columbus Blue Jackets (2020–21) and retirement On 10 October 2020, Koivu ended his 15-year tenure with the Wild and signed as a free agent to a one-year, $1.5 million contract with the
Columbus Blue Jackets. On 9 February 2021, after only posting a goal and an assist for 2 points in 7 games, Koivu announced his retirement from the NHL. ==International play==