Buddies boss Jim Goodwin is eyeing up a deal for former Ross County star Marcus Fraser.
The former Celtic defender is a free agent after leaving the club over the summer.
The Saints have offered him a one-year deal but face competition from English sides Blackpool and Wimbledon for his signature.
Goodwin has already added defenders Richard Tait and Joe Shaughnessy to his side permanently, as well as defensive midfielders Nathan Sheron and Isak Thorvaldsson on loan deals.
Fraser, who helped Ross County lift the Scottish Championship title and Challenge Cup, would boost his backline even further.
St Mirren boss Goodwin is hoping to get a deal over the line before the club's Premiership opener with Livingston this Saturday.
