Saints have signed Polish international keeper Artur Boruc.
The 32-year-old joins as a free agent until the end of the season.
Boruc could quickly find himself as the club's number one.
Kelvin Davis was dropped for the win over Aston Villa with 20-year-old Paulo Gazzaniga his replacement.
Third choice keeper Cody Cropper has picked up an injury which has meant Saints have had to stregnthen.
Boruc, who has 46 caps for his country, started his career in Poland before five successful years at Celtic.
After leaving Scotland he joined Fiorentina in Italy.