Old Firm preview: Rangers' Steven Davis, Celtics' Callum McGregor on what playing in the historic derby means | CBS Sports Headlines Old Firm preview: Rangers' Steven Davis, Celtics' Callum McGregor on what playing in the historic derby means Davis and McGregor sat down with the ¡Qué Golazo! podcast to explain … Continue reading Old Firm preview: Rangers' Steven Davis, Celtics' Callum McGregor on what playing in the historic derby means