Billy Johnstone and Graeme Wynn are both listed as captaining St.George v Balmain on April 26th Rd9 at Leichhardt Oval.
The match report in the SMH mentions Johnstone as the stand in skipper of St.George also with a picture mentioning him as captain.
In the SMH dated Saturday 25/4/87 in an article on team news it mentions the selected captain, Craig Young, is out of the St.George team and lists the team with Billy Johnstone as the new captain.
Young returned as captain the week after v Penrith, with Johnstone as hooker.