That was my first thought.
Too young to remember him as a player or manager (he did make three appearances in the dug out at Meadow Lane as boss of Portsmouth), so I'll always remember him as a TV presenter. His break came when Brian Moore became furious with ITV dropping "On the Ball" in favour of something called "Headline" at the top of the "World of Sport" programme dealing with whatever sport was in the news as well as football, Moore was toying with jumping ship to the BBC and St John was then asked to present "Headline" which soon reverted back to "On the ball" and he ended up doing it full time before it morphed into "Saint and Greavsie" when WOS was axed in 1985.
When Scotland played Peru in the World Cup in 1978 St John was co-commentator with Hugh Johns but the line failed and English viewers ended up hearing Arthur Montford (of Scottish TV) instead. Hugh Johns and St John were supposed to be professional and carry on in case the problem was sorted, so they could go straight back to them, but Hugh Johns stormed out of the commentary area in disgust leaving St John to attempt to commentate on his own and he ended up swearing and cursing throughout and was given a severe dressing down for by his ITV bosses.