He scored an unassisted goal at the 1 minute, 7 second mark of the second period on March 15, 1934. The following season, he moved with the other Senators players to play for the transferred franchise in St. Louis, Missouri known as the St. Louis Eagles in the 1934-35 season. He was sold by the Eagles to the Maple Leafs before the season's end in February 1935 and he finished his career with several seasons with the Maple Leafs as a "defensive specialist." In 1937, Finnigan retired from the NHL. He returned to Ottawa and played ice hockey for various amateur teams, including the Ottawa RCAF Flyers while he was in the Air Force. After retiring from professional hockey, Finnigan went into private business in the Ottawa area. He managed the Olde Colonial Hotel at the corner of O'Connor and Queen Streets in Ottawa. Finnigan sold his shares of the hotel and became head of sales for Brading's Brewery. It was while working at Brading's that Finnigan developed alcoholism and lost his job. He found a job in the federal government through Frank Ahearn, former owner of the Senators, and later Member of Parliament in Ottawa. During World War II, Finnigan joined the Canadian Air Force, and was a member for seven years. Finnigan then owned and managed the Merrickville Hotel in Merrickville, Ontario. Finnigan moved to Shawville and bought the Clarendon Hotel. Finnigan eventually overcame his problems with alcohol and sold the hotel and retired, remaining in the Shawville area. When the NHL planned to expand in 1989, the consortium to obtain a franchise for Ottawa signed Finnigan to be part of the 'Bring Back The Senators' campaign team. Finnigan along with his son Frank Jr., made public appearances on behalf of the campaign. Finnigan was also part of the presentation team to the NHL expansion committee in December 1990. The group was successful and the new Ottawa Senators team began play in the 1992–93 NHL season. Finnigan died before the new team played its first game in 1992, for which he was scheduled to drop the puck for the ceremonial face-off. Instead, on opening night the honour went to his son, Frank Jr. to drop the puck. On that night, the team honoured him by retiring his #8 jersey, making him one of three players in NHL history to have his uniform retired by a team for which he never actually played. Finnigan's number was retired 55 years after he finished his NHL career - the longest wait for a player to have his number retired.