Darren Bent insisted he had to leave Aston Villa after too many "slaps in the face".
Brighton defender Greg Halford has agreed to extend his loan deal from Nottingham Forest until the New Year.
St Mirren have added to their squad ahead of the Scottish Communities League Cup final by completing the signing of Sander Puri.
The Estonia winger, who has 47 caps, has signed until the end of the season with the club having the option to extend his contract for a year.
The 24-year-old is eligible for Sunday's Hampden clash against Hearts and manager Danny Lennon refused to rule out bringing him straight into the squad after he trained with the club throughout this week.
Puri was previously on trial with Kilmarnock after leaving Finnish club KuPS.