John Roberts played in the World Cup qualifier on 21st November 1965. Before moving to Australia he played for Northampton Town, Bradford City, Southend United, Chesterfield, and Blackburn Rovers. However, the captain for that game was Les Scheinflug, according to the rsssf.com webpage above.
The only Aussies who've played for Blackburn Rovers over the last 4 decades are, according to
Australians Overseas, these four: John Roberts, John Filan, Frank Talia and, of course, Robbie Slater ... Filan and Slater played for the Socceroos in the 90s, but Talia didn't play at international level.