Nyman was assigned to Ilves of Finland's Liiga on Monday.
Nyman was signed to a three-year, entry-level contract by Seattle on June 11 after he was selected with the No. 49 pick in the 2022 NHL Entry Draft. The 18-year-old winger had 10 goals and 14 points in 29 appearances with Ilves during the 2022-23 season.