BBC News 24's Mike Bushell reports

It will be the first major championship Sampras has missed for seven years and costs him a chance of equalling Roy Emerson's record of 12 Grand Slam singles titles.

"He obviously had a very long end of year. He played seven weeks in a row in Europe, which is the first time he had done that in his career, obviously with the aim of finishing number on in the world.

The moment of victory (1994)

"He is pretty worn out and needs to take a rest. From an Australian Open perspective, it is disappointing. It was a very big decision for Pete," said tournament director Paul McNamee.

Sampras has won the Australian title on two occasions, beating fellow American Todd Martin 7-6 (7-4) 6-4 6-4 in the 1994 final and defeating Spain's Carlos Moya 6-2 6-3 6-3 two years ago.

"It opens up the race for number one right at the start of the year. There'll be a lot of players thinking they have a chance," McNamee added.