Potter played in nearly every game last season and scored goals against Queen of the South and Motherwell. He was subbed at half time in Saturday's match and went to hospital for X-Rays.
It had been thought (or perhaps hoped) that the foot was just badly bruised, but Saints boss Gus MacPherson confirmed the bad news today. Potter's absence means that Ian Maxwell should get a run in the team, just like he did last season when Kirk Broadfoot broke his foot.
There is still no news on the rumours about midfielder Craig Molloy needing a hernia operation.
Story source: The Official St. Mirren Website