The centre-back has not played for the Championship outfit since injuring his knee in August, but he claims that he has been fit "for a couple of weeks".
"I've been fit for a couple of weeks. I have not been involved because Leicester have been doing very well. Now I want to force my way back in," he told the Leicester Mercury.
"We've got a few centre-halves but the two there have done very well. It's just a case of training and seeing if I can get my chance. They said I can go out on loan, so we'll just have to wait and see what happens."
St Ledger is currently on international duty with the Republic of Ireland.