Gunnar Josef Agaton Holmberg was born on May 6, 1897 in Göteborg and made his IFK Göteborg debut in the 1920 season, which was also the debut season of team mate Gillis Gillås (Andersson). At 23 years, 6 months and 1 day, on November 7, 1920, he took part his first competetive game against Helsingborgs IF in a Svenska serien, div 1 game that ended 0–1. He spent thre seasons with the IFK Göteborgs first team, and during his career he played in 4 first team games. In total, Holmberg has represented his country at the highest level on 12 occasions. Holmberg passed away in 1975, 78 years old.