Relegation-threatened Livorno have sacked Domenico Di Carlo after just 88 days in charge and re-appointed Davide Nicola.
Virgil van Dijk claims he knows nothing of interest from English clubs and is keen to prove himself in the Champions League with Celtic.
The 39-year-old will provide cover to England international John Ruddy, who had been a target for Chelsea, and Mark Bunn.
Norwich had needed back-up after Jed Steer left for Aston Villa and Declan Rudd was loaned out to Preston.
Manager Chris Hughton said: "It is now important to us to bring in a 'keeper of great experience and a player that is used to living life in the Premier League.
"The move also allows us to send Declan Rudd out on an extremely valuable season-long loan to Preston where he can get some first-team football under his belt."