The 42-year-old Australian, who has signed a contract until June 2016, has made over 500 Premier League appearances for Middlesbrough, Fulham and Chelsea.
Leicester's first-choice keeper Kasper Schmeichel suffered a foot injury last month, ruling him out for six weeks as the club battle to stay in the top flight.
They are three points adrift at the bottom of the standings and four points from safety.
(Reporting by Ed Osmond, editing by Toby Davis)
Share
