 Rob Valentine represented South of Scotland (RU) while at Hawick RFC, his last match being the 0-8 defeat by New Zealand in the 1963–64 New Zealand rugby union tour match at Mansfield Park, Hawick on Saturday 16 November 1963, and represented Other Nationalities (RL) while at Huddersfield, he played in the 2-19 defeat by St. Helens at Knowsley Road, St. Helens on Wednesday 27 January 1965, to mark the switching-on of new floodlights.Rob Valentine played left-, i.e.number 8, in Wakefield Trinity's 2-7 defeat by Leeds in the 1973–74 Yorkshire County Cup Final during the 1973–74 season at Headingley Rugby Stadium, Leeds on Saturday 20 October 1973.