Eriks Mateiko is in his third full season with the St. John Sea Dogs in the QMJHL. He scored his first goal of the season on October 5 against the Charlottetown Islanders, earning third star honors for that game. Appointed as the 22nd captain in franchise history on October 9, Mateiko continued to make an impact, scoring in multiple consecutive games. By the end of October, he had tallied seven goals and three assists over 11 games, showcasing his offensive capabilities and leadership on the ice. The Sea Dogs had a balanced record of 8-8 through 16 games.

Eriks Mateiko has signed a three-year entry-level contract with the Capitals, following his selection as the 80th overall pick in the 2024 NHL Draft. The 18-year-old forward had a standout season with the St. John Sea Dogs in the QMJHL, scoring 23 goals and recording 43 points in 49 games, where he also served as an alternate captain. He led his team in goals and power-play goals while making his NHL preseason debut against the Flyers. A native of Jelgava, Latvia, Mateiko represented his country at the 2024 World Junior Championship and previously captained Latvia at the 2023 Under-18 World Championship. He was ranked fifth among North American left wings and 33rd among all North American skaters by NHL Central Scouting.