The Icelander hopes to sign up to three players before the start of the League Two campaign on August 8, with a central defender top of his list of priorities.
"I need two or probably three more players in my squad to make sure we don't start the season on thin ice. Once I get them in I will be happier," Thordarson told the Stoke Sentinel.
"I will try to bring them in before the Wolves and Birmingham (August 4) games so they get time to settle in time for August 8. We are short at centre half and while I can drop Mat Mitchel-King back there if required, I don't want to change my midfield line-up.
"The squad is small. At Hyde we only had 18 players and one of those was a trialist."
Striker Shaun Miller has been struggling with a foot injury but should be available for Wednesday night's game.