[1] After two seasons of Junior A SM-liiga, Koivula secured a two-year Liiga contract with Ilves on 30 March 2016.
After his second full season in the Liiga in 2017–18, Koivula signed a three-year, entry-level contract with the New York Islanders on 21 March 2018.
[3] In his first season in North America, the Bridgeport Sound Tigers developed Koivula to play center, rather than his natural wing position.
He responded with a strong season in a new position, scoring 21 goals and 25 assists for 46 points in 69 games.
[citation needed] Following the 2023–24 season, Koivula left the Islanders as a pending restricted free agent and returned to Scandinavia in signing a two-year contract with Swedish club, Växjö Lakers of the SHL, on 12 July 2024.