In the 1972 â `` 73 NHL season , the St. Louis Blues of the NHL bought Madigan 's rights from the Buckaroos , and he joined the Blues in January 1973 at the age of 38 , becoming the oldest rookie ever . Beset with numerous injuries in the 1972 â `` 73 NHL season , the St. Louis Blues of the NHL bought Madigan 's rights from the Buckaroos , and he suited up for the Blues in January 1973 at the age of 38 , becoming the oldest rookie ever .