Page "Old Firm" Paragraph 5

The ferocity of the rivalry made it rare for a player to represent both teams during his career.

Players who played for both sides of the Old Firm included Alex Bennett, Scott Duncan, Robert Campbell, and George Livingstone, who all played before the intensity of the rivalry had started prior to 1912, as well as later players: Alfie Conn, Maurice Johnston, Kenny Miller, Steven Pressley and Mark Brown.