Poku began playing youth soccer at age six with Brampton East SC.[1] He later played youth soccer with the Woodbridge Strikers, with whom he won the 2017 U14 Ontario Indoor Cup, scoring a hat-trick against Ottawa St. Anthony.[2] He was also part of the provincial Team Ontario that year.[3] He later played for Unionville Milliken SC.[4] He later joined the Toronto FC Academy.[5]
In January 2023, Poku went on trial with Swedish Allsvenskan club BK Häcken.[13] In 2023, he played one game on loan with Forge's affiliate Sigma FC in League1 Ontario.[14] In later September 2023, he was named the CPL player of the week.[15] At the end of the 2023 season, he was nominated for the CPL U21 Player of the Year award.[16][17] In October of the same year, he helped Forge win their fourth league title, following a 2–1 win over Cavalry FC in the play-off final.[18]
During the 2024 season, he was moved from his typical left-back position to centre forward, after several injuries to the team's forwards.[19][20][21] On June 23, 2024, he scored a brace in a 2–1 victory over Valour FC.[22][23] He was named the league's Player of the Month for June 2024.[24] On July 10, he scored a backheel goal against Major League Soccer club Toronto FC in a 2-1 victory in the first leg of the 2024 Canadian Championship semi-finals.[25] On July 14, he scored another brace in a 2–1 victory over Pacific FC,[26] earning league Player of the Week honours.[27] In August 2024, he began to be held out of matches for precautionary reasons, amid transfer interest from foreign clubs.[28][29][30]
Born in Canada, Poku is of Ghanaian descent.[34] In April 2022, he was called up to the Canadian Under-20 team for two matches against Costa Rica.[35] In June 2022, he was named to the Canadian U-20 team for the 2022 CONCACAF U-20 Championship.[36] He appeared in all four of the team's matches, playing a total of 385 minutes, prior to their elimination in the round of 16.[37]