Sigfried Waldemar Mellberg was born on October 1, 1891 in Göteborg and made his IFK Göteborg debut in the 1912 season, which was also the debut season of team mate Valdus Lund. At 23 years, 0 months and 9 days, on October 11, 1914, he took part his first competetive game against Djurgårdens IF in a Svenska serien game that ended 3–7. He spent thre seasons with the IFK Göteborgs first team, and during his career he played in 3 first team games and scored 1 goals. Mellberg passed away in 1963, 71 years old.
It's worth noting that the statistics for players who had their debut ahead of the 1920 season is, or could be, incomplete.