Main signed for Dundee United's Tayside rivals St Johnstone in 1995 for £150,000 as competition for Saints' then first-choice goalkeeper Andy Rhodes. Known for his long kicks and dribbling skills outside his box, Main signed a three-year deal with the Perth club in 1997 and was again called up to the Scotland squad (this time by Craig Brown) not long afterwards. He made the substitutes' bench twice, but with Jim Leighton and Andy Goram ahead of him in the pecking order, he never took to the field.