Seibert first played senior-level hockey with the Berlin Rangers in the Western Ontario Hockey Association (WOHA) in 1900. He played two years with Berlin before switching to Guelph for 1902. He returned and played one further seasons for Berlin. He was a member of Western Ontario Senior championship teams for 1900, 1901, 1902 and 1904. The Berlin team played an exhibition game in St. Louis, Missouri; it is considered one of the first games of ice hockey played on artificial ice. After the WOHA was absorbed into the Ontario Hockey Association (OHA), Seibert was declared ineligible to play in the OHA on December 30, 1904, which eliminated the possibility of play in Ontario.